Catheter for monitoring pressure

ABSTRACT

A catheter insertable into a patient for monitoring pressure having an expandable outer balloon. An expandable inner balloon is positioned within the lumen of the catheter and has having a second outer wall and forms a gas chamber to monitor pressure within the patient. In response to pressure exerted on the outer wall of the outer balloon, fluid within the outer balloon enters an opening in the wall of the catheter lumen to exert a pressure on the outer wall of the expanded inner balloon to deform the inner balloon and compress the gas within the inner balloon. A pressure sensor communicates with the gas containing chamber for measuring pressure based on compression of gas caused by deformation of the expanded inner balloon resulting from deformation of the expanded outer balloon.

This application claims priority from provisional application Ser. No.62/865,360, filed Jun. 24, 2019, and from provisional application Ser.No. 62/771,040, filed Nov. 24, 2018. The entire contents of each ofthese applications are incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

This application relates to a device and method for monitoring pressurein a body cavity.

2. Background

Traditionally, physicians relied on visual cues or physical examinationto detect increase in intra-abdominal pressure (IAP). More recently Dr.Kirkpatrick and colleagues, in an article “Is Clinical Examination anAccurate Indicator of Raised Intra-Abdominal Pressure in CriticallyInjured Patients,” CJS, June 2000, 43, No. 3, 207-211, showed that IAPmeasured through the patient's bladder was significantly more accuratethan physical examination. That is, it was demonstrated that theclinical abdominal examination was insensitive and inaccurate whencompared with urinary bladder pressure measurements.

Various tools for measuring IAP have been developed over the years. Manyresearchers have documented IAP measurements through almost everynatural or manmade orifice in the body. Earlier crude forms of measuringIAP used bladder catheters, nasogastric tubes, and rectal tubes attachedto a manometer. The nasogastric or the rectal route was better suited inrare cases of bladder rupture or situations where bladder catheters werecontraindicated. However, due to local interferences, the nasogastricand the rectal tube measurements were neither reproducible nor logicalas were the bladder catheters.

Thus, measuring of IAP through the bladder became more suitable. In 1989Iberti and colleagues in an article entitled, “Determination ofIntra-abdominal Pressure Using a Transurethral Bladder Catheter:Clinical Validation of the Technique,” Anesthesiology, January 1989,70(1), 47-50, validated the correlation of IAP using a catheter insertedin the bladder. Their study was key in using bladder pressure as thegold standard for measuring IAP. In 1995, Kron and colleagues publisheda study in “The Measurement of Intra-Abdominal Pressure as a Criterionfor Abdominal Re-exploration, 1984 Ann Surg., 199, 28-30, comparingcatheters in various body locations for measuring IAP. They measured IAPfrom the stomach using a nasogastric tube, from the rectum using amodified rectal tube, from the bladder using a modified bladdercatheter, and direct abdominal pressure using a laparoscopic insufflatorneedle. They found that the bladder catheter had the best measurement ofIAP and that the gastric and the rectal catheter measurements were lessreliable due to dependence on the position of the catheter. Thus,clinicians generally agreed that the urinary bladder is the best-suitedlocation for measurement of IAP.

The need for measuring IAP has become more important as physiciansincreasingly realized that organ failure and death were directly relatedto increase in IAP in certain high-risk patients. High abdominalpressure has been found to cause a decrease in function of theintestines, liver and blood vessels resulting in adverse consequencesfor the patients. Consequently, accurate measurement of IAP can helpdecrease patient morbidity and mortality. It has also been more recentlydiscovered that pediatric and neonate population may also have need forIAP measurement to determine specific conditions.

Currently, there are few products available on the market to measure theIAP through the bladder. One device, the Bard IAP device, has a “valveclamp” which diverts urine from the main catheter drainage channel tomeasure IAP via converting hydrostatic pressure to a readable pressuregauge. This mechanism of IAP measurements is archaic and does notprovide continuous pressure measurement when used with the standard2-channel bladder drainage catheter. Two other manufacturers, Holtechand ConvaTec, also use a column of urine by connecting their kit to anexisting bladder catheter. Their systems are cumbersome and the IAPreadings are also not continuous. Biometrix has developed an IAPmonitoring device which like other manufacturers relies on tapping intothe main bladder drainage catheter, using a valve to measure thehydrostatic pressure. In 2008 Sugrue and colleagues, in an article“Prospective Study of Intra-Abdominal Hypertension and Renal Functionafter Laparotomy, British Journal of Surgery, 1999, 82, 235-238,suggested the use of 3-channel bladder drainage catheter so that thesmaller channel, which was used for bladder irrigation, could be used toattach a pressure-monitoring device. The use of an extra channel made itpossible to have continuous bladder drainage while measuring the bladderpressure. However, this bladder catheter did not provide a continuouspressure read because intermittently the operator needed to add 50 ml ofwater or saline to the bladder to record the IAP pressure. Thus, thepressure reading at best was intermittent since pressure readings werenot performed when fluid was being added to the bladder. Consequently,although this was a step toward increasing the amount of pressurereadings/recordings, it still was unable to conduct continuous pressuremonitoring. Furthermore, it was still the same cumbersome IAP device setup which required a skilled person to add water before each IAP reading.Control of the amount of water added is critical since adding too muchwater to the bladder can falsely increase the pressure readings and alsoincrease infection risk, thus further complicating the use.

It has also been recognized that most patients that have a need formeasurement of IAP also need to have continuous drainage of the urinarybladder and thus devices need to account for this process.

Consequently, current devices placed in the bladder for measuringpressure require a continuous water column to maintain pressurereadings. Thus, they fail to measure IAP continuously but only measurepressure intermittently. They also all rely on tapping into an existingbladder drainage catheter, which adds complications. Furthermore, theydo not reduce the complexity of the procedure since they requireconstant retrograde insertion of a relatively large amount of fluid intothe bladder, e.g., 50 cc, which increases the ICU workload. Stillfurther, these devices increase the risk of complications and infectionsassociated with fluid injection into the bladder. Fluid injection isalso complicated since it needs to be closely monitored since too muchfluid in the bladder can give false elevation of IAP readings, causingclinicians to take unnecessary steps in response to what is mistakenlybelieved is excess IAP.

It would therefore be advantageous to provide a device insertable intothe bladder that accurately measures abdominal pressure withoutrequiring adding water to the bladder to obtain such pressure readings.Such device would advantageously avoid the complications and risksassociated with such fluid insertion. Furthermore, it would beadvantageous if such device could continuously measure bladder pressurewithout interruption. This would advantageously enable a constantmonitoring of IAP so critical time periods are not missed. It wouldfurther be advantageous to provide a device that improves the accuracyof the pressure reading in the bladder to more accurately determine IAPso necessary steps can be taken to address IAP only when warranted.Still further, it would be advantageous if such device could satisfy theforegoing needs and provide these enumerated advantages while beingsimple to use so that so that any of clinical staff with basic knowledgeof bladder catheter insertion will be able to insert the device withoutrelying on specially trained staff members. It would also beadvantageous to provide such devices with these advantages for insertioninto other body cavities for accurately measuring pressure within thecavity without the need for injecting fluid into the cavity.

SUMMARY

The present invention overcomes the deficiencies and disadvantages ofthe prior art. The present invention advantageously provides a catheterinsertable into the cavity of the patient to determine pressure withoutrequiring insertion of water or other fluid into the body cavity. Thepresent invention provides catheters insertable into various regions ofthe patient such as the bladder to measure intra-abdominal pressure ormaternal uterine contraction pressure or the uterine cavity to measureintrauterine pressure, the abdominal cavity, etc. The catheters can beused for example in rectal, abdominal, esophageal, cardiac, etc.procedures. The catheters of the present invention utilize a gas-chargedchamber to measure pressure across a large surface area, and thus,accurately determine pressure, and enable pressure to be measuredcontinuously without interruptions to add water to the cavity.

In some embodiments, an outer fluid filled balloon provides a fluidtransmission medium for an inner pressure sensing balloon.

Some embodiments of the catheter of the present invention utilize astabilizing balloon to help retain the catheter in the bladder duringthe procedure.

In accordance with one aspect of the present invention, a catheter isprovided which is insertable into a patient for monitoring pressure. Thecatheter includes a first lumen having a wall and at least one sideopening in the wall and an expandable outer balloon at a distal portionof the catheter. The outer balloon has a first outer wall and receivesfluid to move from a first condition to a more expanded condition, andexpands radially outwardly with respect to the catheter. An expandableinner balloon is positioned within the first lumen of the catheter andhas a second outer wall and an elongated portion extending proximallythrough the first lumen, and has a gas containing chamber to monitorpressure within the patient. The outer balloon has a circumferentialarea greater than a circumferential area of the inner balloon wherein inresponse to pressure exerted on the first outer wall of the expandedouter balloon fluid within the outer balloon enters the at least oneopening in the wall of the lumen to exert a pressure on the second outerwall of the expanded inner balloon to deform the inner balloon andcompress the gas within the inner balloon. A pressure sensorcommunicates with the gas containing chamber for measuring pressurebased on compression of gas caused by deformation of the expanded innerballoon resulting from deformation of the expanded outer balloon.

In some embodiments, the outer balloon is inflated via a second lumenindependent of the first lumen. In some embodiments, the inner balloonin the expanded position remains within the confines of the first lumen.

In some embodiments, a chamber is provided containing a plurality ofopenings communicating with the interior of the outer balloon.

In some embodiments, the catheter includes an additional lumen and astabilizing balloon, the additional lumen communicating with thestabilizing balloon to inflate the stabilizing balloon to stabilize theposition of the catheter. The stabilizing balloon can be positionedproximal of the outer balloon.

In some embodiments, the inner and outer balloons have a coating toincrease impermeability.

In some embodiments, the pressure sensor is contained within a hub andthe hub includes an elongated member extending distally therefrom, andconnection of the hub to a first port of the catheter automaticallyinserts the elongated member into the catheter to advance air into theinner balloon to expand the inner balloon.

In some embodiments, the first lumen is not vented to atmosphere whenthe pressure sensor is connected to the catheter and advances gas toexpand the inner balloon.

In some embodiments, the gas within the inner balloon and/lumen is airto provide an air containing chamber.

In some embodiments, an elongated member is positioned within thetubular portion of the inner balloon to decrease the volume of gaswithin the tubular portion.

In some embodiments, a third balloon is positioned within the outerballoon, the third balloon being less compliant than the outer balloonand forming an inner liner of the outer balloon to maintain an expandedcondition of the outer balloon.

In accordance with another aspect of the present invention, a catheterinsertable into a patient for monitoring pressure within a body cavitywithout insertion of fluid into the cavity is provided, the catheterincluding a wall having at least one side opening and an expandableouter balloon at a distal portion of the catheter having a first outerwall and movable from a first condition to a more expanded condition. Aninner balloon is movable to a more expanded condition, the inner balloonhaving a second outer wall and a gas containing chamber. The secondouter wall of the inner balloon is radially spaced from the first outerwall of the outer balloon, the outer balloon acting as a medium fortransfer of fluid to a second outer wall of the inner balloon to deformthe inner balloon for monitoring fluid pressure. The inner balloon hasan elongated portion extending proximally through a lumen of thecatheter. In response to pressure exerted on the first outer wall of theexpanded outer balloon, fluid within the outer balloon enters the atleast one side opening in the wall of the catheter to exert a pressureon the second outer wall of the expanded inner balloon to deform theinner balloon and compress the gas within the inner balloon to provide apressure measurement. A pressure sensor communicates with the gascontaining chamber of thinner balloon for measuring pressure based oncompression of gas caused by deformation of the expanded inner balloonresulting from deformation of the expanded outer balloon, the pressuresensor measuring pressure at multiple times during a procedure withoutinjecting fluid within the body cavity as the outer balloon provides thefluid transfer medium.

In some embodiments, the elongated portion of the inner balloon alongwith an enlarged portion of the inner balloon forms the gas chamber tomonitor pressure within the patient. In some embodiments, the secondouter wall of the inner balloon does not expand outside the lumen of thecatheter when the inner balloon is in the expanded condition.

In accordance with another aspect of the present invention, a method formeasuring pressure within a body cavity without insertion of fluid isprovided including the steps of:

-   -   a) providing a catheter having an inner balloon and an outer        balloon, a wall of the inner balloon spaced from a wall of the        outer balloon, the inner balloon having a first region with an        outer wall to receive fluid thereon from the outer balloon and        an elongated region communicating with the first region and        extending within a lumen of the catheter;    -   b) inserting the catheter into the body cavity of a patient;    -   c) expanding the inner balloon from a first condition to a more        inflated condition, an internal space of the balloon forming a        gas containing chamber;    -   d) either before or after step (c) expanding the outer balloon        from a first condition to a more inflated condition; and    -   e) obtaining multiple pressure readings within the body cavity        during a procedure based on deformation of the outer balloon        which causes deformation of the inner balloon to thereby monitor        pressure, the outer balloon providing a medium for transfer of        fluid against the outer wall of the inner balloon for multiple        pressure measurements without requiring insertion of fluid into        the body cavity.

The method can include the step of transmitting the pressure readings toan external monitor.

In some embodiments, deformation of the outer balloon is in response topressure exerted on an outer wall of the expanded outer balloon and uponsuch deformation, gas within the outer balloon enters one or moreopenings in the catheter to communicate with the outer wall of theexpanded inner balloon to exert a pressure on and deform the innerballoon and compress the gas within the inner balloon.

The method may further comprise the step of connecting to the catheter ahub containing a pressure transducer to automatically advance gas intothe inner balloon to expand the inner balloon. In some embodiments, thestep of connecting the hub automatically connects a temperature sensorto a connector within the hub.

In accordance with some aspects of the present invention, catheters areinsertable into the bladder and utilized for measuring intra-abdominalpressure. In some such embodiments, the gas containing chamber monitorspressure within the bladder to thereby monitor pressure within anabdomen of the patient. In some embodiments, the pressure transducermeasures average pressure continuously throughout insertion of thecatheter within the urethra without requiring infusion of water into thebladder.

In some embodiments, a second lumen communicates with the bladder toremove fluid from the bladder. In some embodiments, the second lumen hasa side opening distal of the inner and outer balloons; in otherembodiments the side opening is proximal of the inner and outerballoons. The catheter can include a third lumen communicating with theouter balloon to expand the outer balloon.

In some embodiments, the catheter has a fourth lumen and a temperaturesensor positioned within the fourth lumen to measure core bodytemperature. A wire can extend from the temperature sensor through thefourth lumen and external of the catheter into the hub connected to thecatheter. The hub can have a first opening to receive a connector of thewire to automatically connect the temperature sensor to a cableextendable from the hub and connectable to an external temperaturemonitor.

In some embodiments, connection of the pressure sensor to the cathetera) automatically connects the temperature sensor to a temperaturemonitor cable; and b) automatically advances air through the first lumento expand the inner balloon.

In accordance with another aspect of the present invention, a method formeasuring intra-abdominal pressure is provided comprising the steps of:

providing a catheter having first and second lumens, an expandable firstballoon and a temperature sensor;

inserting the catheter through the urethra into a bladder of a patient;

connecting a hub containing a pressure transducer to the first lumen toautomatically advance air through the first lumen of the catheter toexpand the first balloon from a deflated condition to a more expandedcondition and to automatically connect the temperature sensor to aconnector within the hub;

obtaining a first pressure reading of the bladder based on deformationof the balloon without injecting fluid into the bladder;

transmitting the first pressure reading to an external monitor connectedto the hub;

obtaining a second pressure reading of the bladder based on deformationof the balloon without injecting fluid into the bladder;

transmitting the second pressure reading to the external monitorconnected to the hub; and

obtaining consecutive continuous pressure readings of the bladderwithout injecting fluid into the bladder.

The method can further include the step of draining the bladder throughthe second lumen of the catheter. In some embodiments, the step ofobtaining pressure readings obtains average pressure.

In accordance with another aspect of the present invention, amulti-lumen catheter for monitoring intra-abdominal pressure isprovided. The catheter includes an elongated body configured anddimensioned for insertion into a bladder of a patient, a first lumen, asecond lumen, and a third lumen, the lumens being independent. A firstballoon is positioned at a distal portion and the first lumencommunicates with the first balloon. The second lumen communicates withthe bladder to remove fluid from the bladder. The first balloon andfirst lumen are filled with a gas to form a gas filled fully closedchamber to monitor pressure within the bladder to thereby monitorpressure within an abdomen of the patient. A pressure sensor measurespressure within the bladder based on deformation of the first balloon inresponse to pressure within the bladder exerted on an outer wall of theballoon, the pressure sensor measuring bladder pressure continuously andcommunicating with an external monitor to visually display pressurereadings, the sensor providing continuous pressure measurementsthroughout its duration of insertion without requiring infusion of waterinto the bladder.

In accordance with another aspect of the present invention, a system formonitoring intra-abdominal pressure is provided comprising a catheterhaving an elongated body configured and dimensioned for insertion intothe bladder of a patient, a first lumen, a second lumen, a third lumen,and a first balloon at a distal portion. The first lumen communicateswith the first balloon and the second lumen communicates with thebladder to remove fluid from the bladder. The first balloon and firstlumen are filled with a gas to form a gas filled fully closed chamber tomonitor pressure within the bladder to thereby monitor pressure withinan abdomen of the patient. A pressure sensor measures bladder pressurecontinuously and communicates with an external monitor to visuallydisplay pressure readings, the sensor providing continuous pressuremeasurements during its insertion without requiring infusion of waterinto the bladder. An indicator indicates if the measured pressureexceeds a threshold value.

The indicator can be a visual and/or audible indicator.

In accordance with another aspect, the present invention provides amethod for measuring intra abdominal pressure comprising the steps of a)providing a catheter having first and second lumens and a balloon; b)inserting the catheter into a bladder of a patient; c) injecting gasinto the first lumen of the catheter to expand the balloon from adeflated condition to a partially inflated condition; d) obtaining afirst pressure reading of the bladder based on deformation of theballoon without injecting fluid into the bladder; e) transmitting thefirst pressure reading to an external monitor connected to the catheter;f) obtaining a second pressure reading of the bladder based ondeformation of the balloon without injecting fluid into the bladder; g)transmitting the second pressure reading to the external monitorconnected to the catheter; and h) obtaining consecutive continuouspressure readings of the bladder without injecting fluid into thebladder.

The method can include measuring the temperature of a body of a patientutilizing a temperature sensor within the first lumen.

In accordance with another aspect of the present invention, amulti-lumen catheter is provided that is insertable into a patient formonitoring pressure. The catheter comprises an expandable outer balloonat a distal portion of the catheter, the outer balloon having a firstouter wall and receiving fluid to move from a first condition to a moreexpanded condition. A chamber is positioned within the outer balloon andcontains a plurality of openings communicating with the interior of theouter balloon. An expandable inner balloon is positioned within thechamber and has a second outer wall. A first lumen communicates with theinner balloon, the inner balloon and first lumen forming a gas filledchamber to monitor pressure within the patient, wherein the outerballoon has a circumferential area greater than a circumferential areaof the inner balloon, wherein in response to pressure exerted on thefirst outer wall of the expanded outer balloon fluid within the outerballoon enters one or more of the openings in the chamber to exert apressure on the second outer wall of the expanded inner balloon todeform the inner balloon and compress the gas within the inner balloonand the first lumen to provide a finer measurement. A pressure sensorcommunicates with the gas filled chamber for measuring pressure based oncompression of gas caused by deformation of the expanded inner balloonresulting from deformation of the expanded outer balloon.

In accordance with another aspect of the present invention, amulti-lumen catheter insertable into a patient for monitoring pressureis provided, the catheter comprising a shaft having first, second andthird lumens, an expandable outer balloon at a distal portion of thecatheter having an outer wall and receiving fluid via the second lumento move from a first condition to a more expanded condition and achamber positioned within the outer balloon containing a plurality ofopenings communicating with the interior of the outer balloon. Anexpandable inner balloon is positioned within the chamber and has anouter wall and a tubular portion extending within the first lumen. Theouter balloon has a circumferential area greater than a circumferentialarea of the inner balloon, wherein in response to pressure exerted onthe outer wall of the expanded outer balloon, fluid within the outerballoon enters one or more of the openings in the chamber to exert apressure on the outer wall of the expanded inner balloon to deform theinner balloon and compress the gas within the inner balloon. A pressuresensor communicates with the gas within the inner balloon for measuringpressure based on compression of gas caused by deformation of theexpanded inner balloon resulting from deformation of the expanded outerballoon.

In accordance with another aspect of the present invention, amulti-lumen catheter insertable into a patient for monitoring pressureis provided comprising a shaft having a first lumen, a second lumen anda third lumen. The third lumen of the catheter has an opening fordrainage of a cavity. An expandable outer balloon is positioned at adistal portion of the catheter, the outer balloon having an outer walland receiving fluid via the second lumen to move from a first conditionto a more expanded condition. A plug is positioned within the thirdlumen of the catheter to provide a distal region and an expandable innerballoon is positioned within the distal region distal of the plug, theinner balloon having an outer wall and further having a tubular portionextending within the first lumen. The tubular portion has an angledportion so the tubular portion extends from the distal region into thefirst lumen. The outer balloon has a circumferential area greater than acircumferential area of the inner balloon, wherein in response topressure exerted on the outer wall of the expanded outer balloon fluidwithin the outer balloon and exerts a pressure on the outer wall of theexpanded inner balloon to deform the inner balloon and compress the gaswithin the inner balloon. A pressure sensor communicates with the gaswithin the inner balloon for measuring pressure based on compression ofgas caused by deformation of the expanded inner balloon resulting fromdeformation of the expanded outer balloon.

In accordance with another aspect of the present invention, amulti-lumen catheter insertable into a patient for monitoring pressureis provided. The catheter comprises a catheter shaft having a distal endformed of a first material, an expandable outer balloon at a distalportion of the catheter having an outer wall and receiving fluid to movefrom a first condition to a more expanded condition, and an expandableinner balloon positioned within the outer balloon, the inner balloonhaving a second outer wall. A connecting pin is positioned at the distalend of the catheter and is positioned in the distal opening of thecatheter extending distally therefrom. The connecting pin is composed ofmaterial different than the first material and the inner balloon iscomposed of material different than the first material and attached tothe core pin. A first lumen communicates with the inner balloon andextends through the catheter shaft, the first lumen radially spaced fromthe connecting pin. The inner balloon and first lumen form a gas filledchamber to monitor pressure within the patient, wherein the outerballoon has a circumferential area greater than a circumferential areaof the inner balloon, wherein in response to pressure exerted on theouter wall of the expanded outer balloon a pressure is exerted on theouter wall of the expanded inner balloon to deform the inner balloon andcompress the gas within the inner balloon and the first lumen to providea finer measurement. A pressure sensor communicates with the gas filledchamber for measuring pressure based on compression of gas caused bydeformation of the expanded inner balloon resulting from deformation ofthe outer balloon.

In accordance with another aspect of the present invention, amulti-lumen catheter insertable into a patient for monitoring pressureis provided. The catheter includes a catheter body, a first balloon at adistal portion of the catheter balloon having a first outer wallexpandable from a first condition to a more expanded condition and asecond balloon having a second outer wall. The first balloon is externalof the second balloon and the second balloon forms a fluid containingchamber to monitor pressure within the patient. A third balloon ispositioned external of the first balloon such that the first balloon ispositioned within the third balloon, the first balloon being lesscompliant than the third balloon and forming an inner liner of the thirdballoon to maintain an expanded condition of the third balloon. Inresponse to pressure exerted on an outer wall of the expanded thirdballoon fluid within the first balloon enters one or more openings inthe catheter to exert a pressure on the second outer wall of theexpanded second balloon to deform the second balloon and compress thefluid within the second balloon to provide a pressure measurement.

The catheter can include a pressure sensor communicating with the fluidchamber for measuring pressure based on compression of fluids caused bydeformation of the expanded second balloon resulting from deformation ofthe expanded first and third balloons.

In some embodiments the fluid chamber is a gas containing chamber whichcan in some embodiments be an air containing chamber.

In some embodiments, the catheter has a first lumen and the secondballoon has an elongated portion extending through the first lumen andforming an elongated channel, the elongated channel along with thesecond balloon forming the gas filled chamber to monitor pressure withinthe patient.

The catheter can include one or more additional lumens to communicatewith the bladder to remove fluid from the bladder and/or to inflate aretention balloon and/or inflate the first balloon. Preferably, theinner space of the first and second balloons are not in fluidcommunication so they are independently inflatable and deflatable.

The second balloon in some embodiments is maintained centered within thefirst lumen of the catheter so the second outer wall of the secondballoon does not contact an inner wall of the first lumen of thecatheter.

The catheter can have a sensor to measure core body temperature and aplurality of wires extending from the temperature sensor through thecatheter.

In accordance with another aspect of the present invention, a method formeasuring intra-abdominal pressure is provided comprising the steps of:

providing a catheter having an inner balloon, an outer balloon and anintermediate balloon;

inserting the catheter into a bladder of a patient;

expanding the inner balloon from a first condition to a more inflatedcondition, an internal space of the balloon forming a gas containingchamber;

expanding the intermediate balloon from a first condition to a moreinflated condition, wherein expanding the intermediate balloon expandsthe outer balloon from a first condition to a more inflated condition;

obtaining a first pressure reading of the bladder based on deformationof the outer balloon which causes deformation of the intermediateballoon which causes deformation of the inner balloon to thereby monitorpressure; and transmitting the first pressure reading to an externalmonitor connected to the catheter.

In some embodiments, deformation of the outer balloon is in response topressure exerted on an outer wall of the expanded outer balloon, andupon such deformation fluid within the intermediate balloon enters oneor more openings in the catheter to communicate with an outer wall ofthe expanded inner balloon to exert a pressure on and deform the innerballoon and compress the gas within the inner balloon to provide a finerpressure measurement. Preferably, fluid within the intermediate balloondoes not enter inside the inner balloon.

Various uses of the catheter are provided including for example, the gaschamber monitoring pressure within a patient's bladder to therebymonitor pressure within an abdomen of the patient, monitoring pressurewithin a patient's bladder to thereby monitor uterine contractionpressure or monitoring pressure within a uterus of the patient todetermine if excessive pressure is being applied to fallopian tubes ofthe patient.

In some embodiments, connecting a hub containing a pressure transducerto the catheter automatically advances gas into the inner balloon toexpand the inner balloon and can also automatically connect atemperature sensor to a connector within the hub.

BRIEF DESCRIPTION OF THE DRAWINGS

So that those having ordinary skill in the art to which the subjectinvention appertains will more readily understand how to make and usethe surgical apparatus disclosed herein, preferred embodiments thereofwill be described in detail hereinbelow with reference to the drawings,wherein:

FIG. 1A is a side view of a first embodiment of the catheter of thepresent invention having a pressure balloon, a stabilizing balloon and asensor positioned in the air lumen, both balloons shown in the deflated(collapsed) condition;

FIG. 1B is a side view similar to FIG. 1A showing the two balloons inthe inflated (expanded) condition;

FIG. 2 is a schematic view of the system utilizing the catheter of FIG.1A with an alarm system;

FIG. 3 is a close-up view of the tip of the catheter of FIG. 1A;

FIG. 4 is a close-up view of the sensor of FIG. 1A within the air lumen;

FIG. 5 is an enlarged transverse cross-sectional view of the catheter ofFIG. 1 ;

FIG. 6 is an enlarged transverse cross-sectional view of an alternateembodiment of a catheter of the present invention having four lumens;

FIG. 7 is a side view of an alternate embodiment of the catheter of thepresent invention similar to FIG. 1A except having a single balloon, theballoon shown in the inflated condition,

FIGS. 8A and 8B are side views of an alternate embodiment of thecatheter of the present invention having two balloons and a pressuresensor and a separate temperature sensor in the air lumen, the twoballoons shown in the deflated condition, with FIG. 8A showing thedistal end and FIG. 8B showing the proximal end of the catheter;

FIG. 9 is a side view similar to FIG. 8A showing the two balloons in theinflated condition;

FIG. 10A is a close up view of the distal portion of the catheter ofFIG. 8A;

FIG. 10B is an enlarged transverse cross-sectional view of the catheterof FIG. 8A;

FIG. 11 is a side view of another alternate embodiment of the catheterof the present invention having two balloons, a sensor in the air lumenand an external transducer, the two balloons shown in the inflatedcondition;

FIG. 12 is a side view of another alternate embodiment of the catheterof the present invention having two balloons, a temperature sensor inthe air lumen and the pressure sensor external of the catheter, the twoballoons shown in the inflated condition;

FIG. 13A is a side view of another alternate embodiment of the catheterof the present invention having two balloons and a pressure sensorpositioned within the pressure balloon, the two balloons shown in theinflated condition;

FIG. 13B is an enlarged view of the distal portion of the catheter ofFIG. 13A;

FIG. 14A is a side view of another alternate embodiment of the catheterof the present invention having dual pressure sensors, the first sensorpositioned within the air lumen and the second sensor positionedexternal of the catheter, the two balloons shown in the inflatedcondition;

FIG. 14B is an enlarged view of the distal portion of the catheter ofFIG. 14A;

FIG. 15 is a side view of another alternate embodiment of the catheterof the present invention having an outer and inner pressure balloon anda stabilizing balloon, the balloons shown in the inflated condition;

FIG. 16 is a side view similar to FIG. 15 illustrating an alternateembodiment having a larger outer balloon;

FIG. 17A is a side view similar to FIG. 15 illustrating an alternateembodiment having a pear-shaped outer balloon;

FIG. 17B is a side view similar to FIG. 17A showing an alternateembodiment wherein the drainage opening is between the two balloons andshowing an alternate shaped outer balloon;

FIG. 18A is a side view of another alternate embodiment of the catheterof the present invention having a port for connection to an externalpressure transducer and an outer and inner pressure balloon, the twoballoons shown in the inflated condition;

FIG. 18B is close up view of the distal end of the catheter of FIG. 18A;

FIG. 19 is a perspective view of the catheter of FIG. 18A with apressure transducer hub attached to the catheter;

FIGS. 20A, 20B and 20C are enlarged front, side and perspective views ofthe outer balloon of FIG. 18A in the expanded condition;

FIGS. 21A, 21B and 21C are enlarged front, side and perspective views ofthe stabilizing balloon of FIG. 18A in the expanded condition;

FIGS. 22A, 22B and 2C are enlarged front, side and perspective views ofthe inner balloon of FIG. 18A in the expanded condition;

FIG. 23 is a transverse cross-sectional view of the catheter of FIG. 18illustrating the five lumens of the catheter;

FIG. 24A is a cutaway side view showing the pressure transducer hubprior to connection to the catheter of FIG. 18A, a portion of the hubwall and catheter connector removed to show internal components;

FIG. 24B is a side view similar to FIG. 24A showing the hub attached tothe catheter;

FIG. 25A is a perspective view of the transducer hub of FIG. 24A;

FIG. 25B is a perspective view of the proximal end of the cathetershowing a connector for the thermocouple wire;

FIG. 26 is a side view of alternate embodiment of the pressuretransducer hub having a shroud over the elongated member for snapfitting onto the catheter;

FIG. 27 is a schematic view of an alternate embodiment of the pressuretransducer hub extendable into two side ports of the catheter;

FIG. 28A is a perspective view of an alternate embodiment of thetransducer hub and connector;

FIG. 28B is a cutaway side view of the hub and connector of FIG. 28Ashowing the pressure transducer prior to connection to the catheter ofFIG. 18A, a portion of the hub wall and connector removed to showinternal components;

FIG. 28C is a cutaway side view similar to FIG. 28B showing the hubattached to the catheter;

FIG. 28D is a cutaway side view similar to FIG. 28B from the other side;

FIG. 29A is a cutaway side view of the hub and connector of an alternateembodiment showing the pressure transducer prior to connection to thecatheter of FIG. 18A, a portion of the hub wall and catheter connectorremoved to show internal components

FIG. 29B is a cutaway side view of the hub and connector of FIG. 29A;

FIG. 29C is a cutaway view similar to FIG. 29B showing the hub attachedto the connector of FIG. 29A;

FIG. 30A is a side view of an alternate embodiment of the catheter ofthe present invention;

FIG. 30B is an exploded side view of the catheter of FIG. 30A;

FIG. 30C is an enlarged transverse cross-sectional view of the catheterof FIG. 30A;

FIG. 31 is a close up exploded view of the distal end of the catheter ofFIG. 30A;

FIGS. 32A, 32B, 32C and 32D illustrate the manufacturing steps ofassembly of the catheter of FIG. 30A wherein FIG. 32A shows theconnecting pin inserted into the catheter shaft; FIG. 32B shows theinner balloon attached to the connecting pin; FIG. 32C shows the distaltip connected to the pin; and FIG. 32D shows the outer balloon attachedto the shaft and distal tip;

FIG. 33 is a side perspective of the distal end of the catheter of FIG.30A showing the balloons in the deflated condition;

FIG. 34 is a close up view of the outer balloon of FIG. 33 in thedeflated condition shown folded over itself;

FIG. 35 is a side view of the distal region of the catheter of analternate embodiment;

FIG. 36 is a view similar to FIG. 35 with the outer balloon removed forclarity;

FIG. 37 is a perspective view of the inner balloon chamber of thecatheter of FIG. 35 ;

FIG. 38 is a cutaway view of the chamber of FIG. 37 ;

FIG. 39 is a view similar to FIG. 35 with the outer balloon and chamberremoved for clarity;

FIG. 40 is a cutaway view of the catheter of FIG. 35 ;

FIG. 41 is a perspective view of the inner balloon of the catheter ofFIG. 35 ;

FIG. 42 is a perspective view of an alternate embodiment of the innerballoon chamber;

FIG. 43 is a perspective view of the chamber of FIG. 42 from the otherside;

FIG. 44 is a cutaway view of the chamber of FIG. 43 ;

FIG. 45A is a longitudinal cross-sectional view of the distal region ofa catheter of an alternate embodiment containing the chamber of FIG. 42;

FIG. 45B is a transverse cross-sectional view taken along line A-A ofFIG. 45A;

FIG. 46A is a cutaway view similar to the cross-sectional view of FIG.45A;

FIG. 46B is a perspective view of the distal end of the catheter of FIG.46A;

FIG. 47A is a longitudinal cross-sectional view of the distal region ofan alternate embodiment of the catheter of the present invention;

FIG. 47B is a transverse cross-sectional view taken along line A-A ofFIG. 47A;

FIG. 47C is a cutaway view similar to the cross-sectional view of FIG.47A;

FIG. 48A is a perspective view of the distal end of the catheter of FIG.47A;

FIG. 48B is a perspective view of the distal tip of the catheter of FIG.47A;

FIG. 48C is a perspective view of the plug of the catheter of FIG. 47A;

FIG. 49 is a side view of an alternate embodiment of the catheter of thepresent invention;

FIG. 50A is a side view of an alternate embodiment of the catheter ofthe present invention showing the balloons in the inflated condition;

FIG. 50B is a side view of an alternate embodiment of the catheter ofFIG. 50A having an additional port for the thermistor wires;

FIG. 50C is a side view of the proximal portion of the catheter of FIG.50A;

FIG. 51 is a close up view of the distal end of the catheter of FIG. 50Awith the balloons in the inflated condition;

FIG. 52 is a cross-sectional view of the catheter of FIG. 50A;

FIG. 53 is a front view of the catheter of FIG. 50A;

FIG. 54 is a cutaway side view illustrating the inside of a cathetersimilar to the catheter of FIG. 50A;

FIG. 55 is an enlarged view of the distal tip of the catheter of FIG.50A;

FIG. 56 is a side view of a portion of the shaft of the catheter of FIG.50A showing the openings for communicating with the outer wall of theinner balloon;

FIG. 57 is a side view of a portion of the shaft of the catheter of FIG.50A showing the drainage opening;

FIG. 58A is a longitudinal cross-sectional view of the catheter shaft ofFIG. 56 ;

FIG. 58B is a transverse cross-sectional view taken along line B-B ofFIG. 56 ;

FIG. 58C is a transverse cross-sectional view taken along line C-C ofFIG. 57 ;

FIG. 58D is a transverse cross-sectional view taken along line D-D ofFIG. 57 ;

FIG. 59A is a perspective view of the retention balloon of the catheterof FIG. 50A;

FIG. 59B is a cross-sectional view of the retention balloon of FIG. 59A;

FIG. 60A is a side view of the inner balloon of the catheter of FIG.50A;

FIG. 60B is a side view of the distal outer balloon of the catheter ofFIG. 50A;

FIG. 60C is a side view of the intermediate balloon (inner liner) of thecatheter of FIG. 50A;

FIG. 60D is a side view of an insert for the inner balloon in accordancewith an alternate embodiment;

FIGS. 61A and 61B are side views of the distal tip of the catheter ofFIG. 50A;

FIG. 62 is a front view of the distal inner sleeve of the catheter ofFIG. 50A;

FIG. 63A is a front view of the proximal plug of the catheter of FIG.50A;

FIG. 63B is a perspective view of the proximal plug of FIG. 63A;

FIG. 64 is a perspective view of an alternate embodiment of the hub andconnector of the present invention;

FIG. 65 is a cutaway side view of the hub and connector of FIG. 64 ;

FIG. 66A is an exploded perspective view of a hub and connector of FIG.64 ;

FIG. 66B is an exploded perspective view of the connector showing thethermistor wires;

FIG. 66C is an exploded perspective of the connector of FIG. 64 showingthe thermistor wires;

FIGS. 67 and 68 are exploded perspective views of the hub and connectorof FIG. 64 ;

FIG. 69 is an exploded side view of the hub and connector of FIG. 64 .

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Increased abdominal pressure can cause many adverse conditions includingdiminishing the function of the intestines, liver, and blood vessels.Simply viewing or feeling the abdomen does not provide sufficientinformation or reading of health conditions.

It is recognized that urinary bladder pressure directly correlates tothe intra-abdominal pressure. Although pressure readings can bedetermined by access to the esophagus or rectum, the bladder has beenfound to be the most accurate and the least invasive. In trauma or burnpatients for example, time is critical and the less complicated themethod for determining bladder pressure the better the clinical results.

The catheters of the present invention measure abdominal pressure viameasurement of bladder pressure without filling the bladder with water.This avoids the risks associated with retrograde filling of the bladderwith water as such retrograde filling not only increases thecomplications and workload for the intensive care (IC) staff and cancreate inaccuracies by providing false elevation of IAP readings, butcan adversely affect the patient by increasing the risk of infection.Furthermore, by avoiding refilling of the bladder, bladder pressure canbe measured continuously. This is because in devices requiring fillingthe bladder with water, water needs to be periodically added to thebladder to replace the water drained from the bladder and measurementreadings are interrupted during water insertion. Due to these repeatedinterruptions, pressure cannot be read continuously. Note in some cases,as much as 50 cc of fluid needs to be repeatedly added to the bladder.

The catheters of the present invention efficiently and effectivelymeasure bladder pressure without requiring filling the bladder withwater. Also, as will become apparent from the discussion below, thecatheters of the present invention provide a more accurate reading ofpressure and enable continuous monitoring of the bladder pressure. Thisis all achieved in an easy to insert device.

It should be noted that the catheters of the present invention can beutilized for measuring other pressure in a patient and are not limitedto intra-abdominal pressure. The catheters of the present invention canalso be inserted into a variety of body cavities of the patient and canbe used for monitoring pressure of various body regions. These catheterscan be used in various body cavities for measuring pressure withoutrequiring insertion of water into the body cavity and thus have thenumerous advantages associated with requiring water as described herein.

Furthermore, in some embodiments, the catheters of the present inventionhave a dual sensor to provide a backup pressure reading. In someembodiments, a dual pressure balloon arrangement is provided. Thesevarious embodiments are discussed in more detail below.

Referring now to the drawings and particular embodiments of the presentinvention wherein like reference numerals identify similar structuralfeatures of the devices disclosed herein, there is illustrated in FIGS.1A-5 a catheter of a first embodiment of the present invention. Thecatheter (device) is designated generally by reference numeral 10 and isconfigured for insertion into and positioning within the bladder of thepatient for measuring intra-abdominal pressure, although it can be usedto measure pressure of other body regions and inserted into other bodyregions. This measurement is to check if the intra-abdominal pressureexceeds a specified threshold since if such threshold is exceeded, thereis a risk to the patient as discussed above and steps need to be takento reduce the pressure such as draining additional fluid from theabdomen, opening the abdomen, etc.

The catheter 10 of the present invention can in some embodiments includean alarm or indicator to alert the user if pressure within the bladder,which correlates to pressure within the abdomen, rises to anunacceptable level, i.e., beyond a threshold or predetermined value(pressure). The indicator or alarm can be on the catheter oralternatively on an external device such as the monitor as discussed inmore detail below. The alarm can also be connected via wirelessconnection to a phone or remote device to alert the appropriatepersonnel. The indicator or alarm can alternatively or in addition beactivated if a change in pressure measurement exceeds a specified rateover a specified period of time.

Turning now to details of the catheter 10, which is also referred toherein as the device 10, and with initial reference to FIGS. 1A, 1B, 3and 4 the catheter 10 of this embodiment has an elongated flexible shaft12 having a lumen (channel) 14 extending within the shaft 12 andcommunicating at its distal region with balloon 16 to fluidlycommunicate with balloon 16 to inflate the balloon. Balloon 16 isutilized for monitoring pressure and is also referred to herein as the“pressure balloon.” A fluid port 15 is positioned at a proximal region17 of the catheter 10 for communication with an infusion source forinfusion of gas, e.g., air, through the lumen 14 and into the balloon16. The catheter 10 is shown in FIG. 1A with balloon 16 in the deflatedcondition (position) and in FIG. 1B with the balloon 16 in the inflatedcondition (position). The shaft 12 also includes a second lumen(channel) 20 and third lumen (channel) 24 extending therein (see alsoFIG. 5 ). In a preferred embodiment, the second lumen 20 is the largestlumen and is configured for continuous drainage of bodily contents fromthe bladder and can be connected to a drainage bag for collection ofurine. Second lumen 20 has a side opening 22 at a distal portion, bestshown in FIG. 3 , communicating with the bladder. The third lumen 24terminates at its distal end within balloon 26 to fluidly communicatewith balloon 26 to inflate the balloon 26. The balloon 26 is inflatableto stabilize the catheter 10 to limit movement of the catheter 10 tokeep it in place within the bladder and is also referred to herein as“the stabilizing balloon 26.” A fluid port 28 is positioned at aproximal region 17 of the catheter 10 for communication with an infusionsource for infusion of fluid through the lumen 24 and into the balloon26. The balloon 26 can be filled with fluid, e.g., liquid such as wateror saline, or a gas, e.g., air. In FIG. 1A, the balloon 26 is shown inthe deflated condition and in FIG. 1B in the inflated condition.

Note FIG. 5 is a transverse cross-section of the catheter showing thethree lumens of various shapes. These cross-sectional shapes of thelumens are provided by way of example as one or more of the lumens canbe circular, oval or other symmetrical or asymmetrical shapes intransverse cross section. This also applies to the cross-sectional viewsof the other embodiments herein, e.g., FIGS. 6, 10B and 23, 30C, 45B,wherein the lumens can be shapes other than those shown. As noted above,preferably the drainage lumen is the largest lumen but in alternateembodiments one or more of the other lumens could be larger than thedrainage lumen.

A sensor 30 is positioned within lumen 14 adjacent balloon 16. Thewire(s) 32 are shown extending through lumen 14, the sensor 30 andwire(s) 32 being of sufficiently small size so as not to interfere withair flow though lumen 14. The sensor 30 measures pressure of thebladder. The sensor 30 is part of a transducer for converting thevariation in pressure to an electrical signal for transmission to anexternal monitor. The pressure sensor can also include a temperaturesensor, or alternatively another sensor for sensing temperature could beprovided, to measure core temperature of the body as seen inside thebladder. Transmission wire(s) 34 of the temperature sensor extendadjacent wire 32 through lumen 14 and terminate external of the catheter10 for connection to an external monitor. The transducer can be wireddirectly to the monitor or alternatively wired to a converter externalof the catheter for converting the signal received by the transducer andtransmitting a signal to the monitor, e.g., a bedside monitor, todisplay the pressure readings. This is shown schematically in FIG. 2 .The readings can be displayed in quantitative form, graphical form orother displays to provide an indicator to the clinician of the bladderpressure. The monitor, or a separate monitor, will also display thetemperature readings from sensor 30. Alternatively, thesensor/transducer can be connected to the monitor via a Bluetoothwireless connection.

Wires 32 and 34 can extend though lumen 14 and exit side port 15 forconnection to a converter or monitor or alternatively can be insertedthrough the lumen 14, piercing the wall to enter the lumen 14 distal ofthe side port.

An alarm system can also be provided wherein the system includes acomparator for comparing the measured pressure (and/or temperature) to athreshold (predetermined) value, and if such threshold is exceeded, anindicator, e.g., an alarm, is triggered to indicate to the hospitalpersonnel the excessive pressure and/or temperature. An alarm system canalternatively or in addition be activated if a change in pressuremeasurement exceeds a specified rate over a specified period of time.This would alert the staff to an imminent risk prior to intra-abdominalpressure exceeding a certain value, e.g., 20 mm hg, since due to thislink, the relationship between intra-abdominal pressure and abdominalcavity volume is believed to be linear up to an intra-abdominal pressureof 12-15 mm hg and increasing exponentially thereafter.

The alarm system can be part of the catheter (as shown in FIG. 2 ) oralternatively external to the catheter 10.

The lumen 14 and space 16 a within balloon 16 together form a closedgas, e.g., air, chamber, i.e., the lumen 14 forming an air column. Withthe balloon 16 filled with air, pressure on the external wall of theballoon will force the balloon to deform inwardly, thereby compressingthe air contained within the balloon space 16 a and within the lumen 14.The pressure sensor 30 is located in a distal portion of the lumen 14 atthe region of the balloon 16 and thus is positioned at the distal end ofthe air column. Therefore, the pressure is sensed at the distal regionas the sensor 30 detects change in air pressure in lumen 14 due toballoon deformation. Placement of the sensor 30 at a distal locationprovides a pressure reading closer to the source which advantageouslyincreases the accuracy because it reduces the risk of transmissionissues by reducing the amount of interference which could occur due towater, air, clots, tissue, etc. if the transmission is down the airlumen (air column).

Additionally, the pressure measurement occurs about a morecircumferential area of the balloon 16 providing a pressure reading of aregion greater than a point pressure sensor reading. Also, averagepressure over an area of the bladder wall can be computed. Thus, thearea reading gleans information on pressure over more of the bladderwall. Stated another way, the balloon has a relatively large surfacearea with multiple reference points to contribute to average pressurereadings of the surface around it by the sensor.

The air column is charged by insertion of air through the side port 15which communicates with lumen 14. The side port 15 includes a valve toprovide a seal to prevent escape of air from a proximal end. The balloon16 can be composed of impermeable material, or in alternativeembodiments, a permeable or semi-permeable material with an impermeablecoating. This seals the air column at the distal end to prevent escapeof air through the distal end, i.e., through the wall of the balloon 16.Thus, with the lumen sealed at the proximal and distal ends, a closedair system is provided, and without the requirement for repeated waterinsertion, a fully closed unit is provided.

In some embodiments, when the lumen 14 is air charged, the balloon 16 isnot fully inflated. This improves the accuracy of the balloon 16transmitting pressure from external the balloon to the interior of theballoon and into the lumen, i.e., air column, by ensuring the balloonhas sufficient compliancy to prevent the balloon from introducingartifact into the pressure reading which would diminish its accuracy.

In some embodiments, the pressure balloon 16 is of a size to receive atleast about 3 cc (3 ml) of fluid. However, other sizes/volumes are alsocontemplated such as about 2 cc or about 1 cc. Additionally, thesevolumes represent the maximum volume of fluid for the balloon, however,as noted above, in preferred embodiments, the pressure balloon 16 is notfully inflated so it would receive less than the maximum volume. Thus,with a balloon of X volume, the fluid would receive X-Y fluid, with Yrepresenting the amount of desired extra space to achieve desiredcompliancy of the balloon while still enabling sufficient inflation ofthe balloon to achieve its pressure induced deformation function.

Note in this embodiment, the stabilizing balloon 26 is positionedproximal of the pressure balloon 16. Also, in this embodiment, thestabilizing balloon 26 is larger than the pressure balloon 16. By way ofexample, the stabilizing balloon 26 can have a fully expanded diameterof about 23 mm and the pressure balloon 16 can have a fully expandeddiameter of about 15 mm, although other dimensions or diameters forthese balloons are also contemplated. By way of example, the stabilizingballoon 26 can have a capacity of about 10 cc (10 ml) of air, althoughother sizes/volumes are also contemplated. Note these sizes/volumes forboth balloons are provided by way of example and other sizes are alsocontemplated. Alternatively, the stabilizing balloon can be the samesize or smaller than the pressure balloon. Various shapes of theballoons are also contemplated.

Additionally, although the balloon 26 is positioned proximal of theballoon 16, it is also contemplated that the balloon 26 be positioneddistal of balloon 16. The axial spacing of the balloons 16, 26 enablethe stabilizing balloon 26 to engage the bladder wall to provide asufficient radial force thereon for securing/mounting the catheterwithin the bladder without interfering with the function of balloon 16.

It should be appreciated that although the stabilizing balloon is shownin the embodiment of FIG. 1 , it is also contemplated as an alternativethat the catheter and system of FIGS. 1 and 2 can be utilized withoutthe stabilizing balloon 26 as shown for example in FIG. 7 . Similarly,although the various embodiments (catheter) disclosed herein utilize astabilizing balloon, it is also contemplated that alternatively thecatheter of these various embodiments not include a stabilizing balloon.In the embodiment of FIG. 7 , catheter 50 has two lumens: 1) a lumen fordrainage of the bladder which has a side opening at a distal end tocommunicate with the bladder (similar to lumen 20 of FIG. 1A); and 2) anair lumen filling pressure balloon 16 via insertion of air through sideport 55. The sensor 30 is positioned within the air lumen in the samemanner as sensor 30 is in lumen 14 or in the alternative positionsdisclosed herein. Thus, the pressure and temperature sensing describedin conjunction with FIG. 1 is fully applicable to the embodiment of FIG.7 . Besides the elimination of the stabilizing balloon and its lumen andside port, catheter 50 is the same as catheter 10,

Note that although only one sensor is shown in FIG. 3 , it is alsocontemplated that multiple sensors can be provided. Also, note that thesensor 30 is positioned in lumen 14 at a mid-portion of the balloon,i.e., just proximal where the opening in lumen 14 communicates with theinterior 16 a of the balloon 16. It is also contemplated that the sensorcan be placed at another portion within the lumen 14, e.g., a moreproximal portion, with respect to the lumen opening for the balloon.Also, the lumen opening for the balloon need not be at the mid portionof the balloon and can be at other regions of the balloon to communicatewith the interior space 16 a. Note if multiple sensors are provided,they can be positioned at various locations within the lumen 14.

As shown, the sensor 30 and its transmission wires are located in thesame lumen 14 also used for initial inflation gas, e.g., air, forballoon 16 and for the air charged column. This minimizes the overalltransverse cross-section (e.g., diameter) of the catheter 10 byminimizing the number of lumens since additional lumens requireadditional wall space of the catheter. However, it is also contemplatedin an alternate embodiment that the sensor is in a dedicated lumenseparate from the inflation lumen 14. This can be useful if a largersensor or additional wires are utilized which would restrict the airlumen if provided therein. This is also useful if a specific sized lumenfor the sensor and wires is desired to be different than the sized lumenfor the air column. Provision of a separate lumen is shown in thecross-sectional view of FIG. 6 wherein in this alternate embodimentcatheter 40 has four lumens: 1) lumen 42 for drainage of the bladderwhich has a side opening at a distal end to communicate with the bladder(similar to lumen 20 of FIG. 1 ); 2) lumen 44 for filling pressureballoon 16; 3) lumen 46 for filling stabilizing balloon 26; and 4) lumen50 in which sensor 30 and its transmission wires 32 and temperaturesensor wires 34 are contained. In all other respects catheter 40 isidentical to catheter 10 and its balloons, air channel, sensor, etc.would perform the same function as catheter 10. Therefore, for brevity,further details of catheter 40 are not discussed herein as thediscussion of catheter 10 and its components and function are fullyapplicable to the catheter 40 of the embodiment of FIG. 6 . As notedabove, the cross-sectional shapes of the lumens can be circular, oval,etc. or other symmetrical or asymmetrical shapes.

Turning now to the use of the catheter 10, the catheter 10 is insertedinto the bladder. Note catheter 50 would be used in the same manner. Theballoon 26 is inflated to secure the catheter 10 in place during theprocedure by insertion of a fluid (liquid or gas) through side port 28which is in fluid communication with lumen 24. The system is charged byinflation of the balloon 16, i.e., preferably partial inflation for thereasons discussed above, by insertion of air via a syringe through port15 which is in fluid communication with lumen 14. As discussed above,the catheter 10 is a closed system with the balloon 16 sealed so thatair inserted through lumen 14 and into balloon 16 cannot escape throughballoon 16. Thus, a closed chamber is formed comprising the internalspace 16 a of the balloon 16 and the internal lumen 14 communicatingwith the internal space 16 a of balloon 16. With the balloon 16inflated, pressure monitoring can commence. When external pressure isapplied to an outer surface 16 b of the balloon 16, caused by outwardabdominal pressure which applies pressure to the bladder wall and thusagainst the wall of balloon 16, the gas e.g., air, within the chamber iscompressed. The sensor 30 at the distal end of lumen 14 providescontinuous pressure readings, converted to an electrical signal by thetransducer within the distal end of lumen 14, and then electricallycommunicates through wire(s) 32 extending through lumen 14, exitingthrough the proximal side port 15 and connected to an external monitor.Note the wire can terminate at the proximal end in a plug in connectorwhich can be connected directly to the monitor or alternatively pluggedinto a converter to convert the signals from the transducer in theembodiments wherein the converter is interposed between the wires andmonitor (see e.g., the system of FIG. 2 ) to provide the aforedescribedgraphic display. Although, the system is capable of continuous pressureand temperature monitoring, it can also be adapted if desired forperiodic monitoring so the pressure and/or temperature readings can betaken at intervals or on demand by the clinician.

In the embodiments wherein an indicator is provided, if the measuredpressure exceeds a threshold value, and/or a change in pressuremeasurement exceeds a specific rate over a specific time period, theindicator would alert the clinician, e.g., via a visual indication or anaudible indication that the threshold is exceeded. The indicator in someembodiments can include an audible or visual alarm (shown schematicallyin FIG. 2 ). In the embodiments having an indicator, the indicator canbe provided on a proximal end of the catheter which extends out of thepatient or the indicator can be part of an external component such asthe monitor or a separate alarm system. A visual, audible, or otherindicator can likewise be provided in any of the other embodimentsdisclosed herein to indicate if the measured temperature exceeds apredetermined value, and such indicator can include an alarm and can bepart of the catheter or a separate component.

In the embodiments of FIGS. 1-7 , within the distal end of the air lumen14 is a pressure transducer and pressure sensor 30 which also includes atemperature sensor. In the alternate embodiment of FIGS. 8A-10B, thetemperature sensor is separate from the pressure sensor. Morespecifically, catheter 60 has an elongated flexible shaft 62 having alumen (channel) 64 extending within the shaft 62 and fluidlycommunicating at a distal region with balloon 66 to inflate the balloon.Balloon 66 (also referred to as the pressure balloon) is utilized formonitoring pressure. A fluid side port 65 is positioned at a proximalregion 67 of the catheter 60 for communication with an infusion sourcefor infusion of gas e.g., air, through the lumen 64 and into the balloon66. The catheter 60 is shown in FIG. 8A with balloon 66 in the deflatedcondition (position) and in FIG. 9 with the balloon 66 in the inflatedcondition (position). The shaft 62 also includes a second lumen(channel) 70 and third lumen (channel) 74 extending therein. The secondlumen 70 is preferably the largest lumen and is configured for drainageof the bladder. Second lumen 70 has a side opening 72 at a distalportion communicating with the bladder. The third lumen 74 communicatesat a distal region with stabilizing balloon 76 to fluidly communicatewith balloon 76 to inflate the balloon. The stabilizing balloon 76 isinflatable to stabilize the catheter 60 to limit movement of thecatheter 60 to keep it in place within the bladder. A side fluid port 75is positioned at a proximal region 67 of the catheter 60 forcommunication with an infusion source for infusion of fluid through thelumen 74 and into the balloon 76.

Sensor 80 is positioned in lumen 64 for sensing pressure in response toballoon deformation in the same manner as sensor 30. Sensor 82 ispositioned in lumen 64 distal of sensor 80 for measuring coretemperature. Temperature sensor 82 can be a thermocouple, a thermistoror other types of temperature sensors. As shown in FIG. 9 , thetemperature sensor is distal of the balloon 66 and its transmissionwire(s) 83 extend proximally within lumen 64, exiting a proximal end(through side port 65) for communication with a monitor or alternativelya converter which communicates with the monitor. Wire(s) 81 of sensor 80also extends through lumen 64, alongside wire 83, exiting through theside port 65 or a proximal end wall or a side wall of the lumen. It isalso contemplated that alternatively one or both of sensors 80 and 82,and their associated wires 81, 83, can be positioned in a separate“fourth” lumen such as in the embodiment of FIG. 6 so that the“inflation lumen” and the “sensor lumen” are independent.

In use, catheter 60 is inserted into the bladder and stabilizing balloon76 is inflated to secure the catheter 60 in place. The system is chargedby inflation of the balloon 66, i.e., preferably partially inflated forthe reasons discussed above, by insertion of gas, e.g., air, throughport 65 which is in fluid communication with lumen 64 in a closed systemformed by the internal space 66 a of the balloon 66 and the internallumen 64 communicating with the internal space 66 a of balloon 66. Withthe balloon 66 inflated, pressure monitoring can commence as externalpressure applied to an outer surface of the balloon 66 compresses thegas within the gas containing chamber. The sensor 80 at the distal endof lumen 64 provides continuous pressure readings, converted to anelectrical signal by the transducer within the distal end of lumen, andthen electrically communicates through wires 82 extending through lumen64 to an external monitor either directly or via a converter. The sensor82 at the distal end of lumen 64 provides continuous temperaturereadings via wires 83 communicating directly or indirectly with themonitor, Although, the system is capable of continuous pressure andcontinuous temperature monitoring, as with the other systems disclosedherein, it can also be adapted if desired for periodic monitoring so thepressure and/or temperature readings can be taken at intervals or ondemand by the clinician.

In the alternative embodiment of FIG. 11 , catheter 90 is identical tothe catheter 60 of FIG. 8 except that the pressure transducer ispositioned external of the catheter rather than in the air (or othergas) lumen. That is, instead of the pressure transducer including thesensor being positioned within the distal end of the air lumen, thepressure sensor 92 is positioned within lumen 94 at the distal end ofthe lumen and transmission wire(s) 93 connect the sensor 92 to thepressure transducer 96 positioned outside of the patient at a proximalregion of catheter 90. As shown, the pressure transducer 96 can bepositioned in a side port of catheter 90. In alternate embodiments, itis positioned outside the catheter. In alternate embodiments, thepressure sensor acts as a transducer and is positioned outside thepatient at a proximal region of the catheter or alternatively positionedin a side port. The temperature sensor 95 is positioned within lumen 94along with transmission wire 97 in the same manner as temperature 82 andwires 83 are positioned in catheter 60 described above. The temperaturesensor 95 can be a separate sensor positioned distal of the pressuresensor 92 as shown or alternatively it can be part of sensor 92 as inthe embodiment of FIG. 1 . In all other respects, catheter 90 isidentical to catheter 60 and therefore for brevity further discussion isnot provided since the structure and function of the balloons, thecontinuous pressure monitoring, etc., as well as the aforedescribedalternative arrangements of catheter 60, are fully applicable to thecatheter 90.

In the alternative embodiment of FIG. 12 , catheter 100 is identical tocatheter 60 of FIG. 8 except that the pressure transducer and pressuresensor are positioned external of the patient at a proximal region ofthe catheter rather than in the air lumen. That is, instead of thepressure transducer/sensor being positioned within and at the distal endof the air lumen, the transducer/pressure sensor 102 are positioned at aside port 103 of the catheter 100. In alternative embodiments, they arepositioned outside the catheter. In yet other embodiments, the pressuresensor/pressure transducer can be positioned within the air (or othergas) lumen at a proximal end of the air lumen. The temperature sensor107 is positioned within lumen 104 along with transmission wire(s) 108in the same manner as temperature sensor 82 and wire 83 are positionedin catheter 60 described above. The system is charged by inflation ofthe balloon 106, i.e., preferably partially inflated for the reasonsdiscussed above, by insertion of air via a syringe or other injectiondevice through the side port 103 which is in fluid communication withlumen 104. The catheter 100 is a closed system with the balloon 106sealed so that air inserted through lumen 104 and into balloon 106cannot escape through balloon 106. Thus, a closed chamber is formedcomprising the internal space of the balloon 106 and the internal lumen104 communicating with the internal space of balloon 106. With theballoon 106 inflated, pressure monitoring can commence. When externalpressure is applied to an outer surface of the balloon 106, caused byoutward abdominal pressure which applies pressure to the bladder walland thus against the wall of balloon 16, the gas (e.g., air) within thechamber of the balloon 106 is compressed. This compresses the air withinthe lumen 104 creating an air charged column along the lumen 104. Thesensor 102 at the proximal end of catheter 100 measures pressure of theair column at its proximal end and can provide continuous pressurereadings, converted to an electrical signal by the transducer at theproximal end or external of the catheter 100, and then electricallycommunicates through wire(s) to an external monitor. The balloon 106,like balloon 16, balloon 66 and the other pressure balloons describedherein, is of sufficiently large size to provide a sufficientcircumferential area for detection of pressure changes along severalparts of the bladder wall, thereby providing an average pressure andenabling more accurate pressure readings. Balloon 109 is a stabilizingballoon like balloon 76 inflated through a separate lumen.

Note the wire(s) of the sensor 102 can terminate at the proximal end ina plug in connector which can be connected directly to the monitor oralternatively plugged into a converter to convert the signals from thetransducer in the embodiments where the converter is interposed betweenthe wires and monitor (see e.g. the system of FIG. 2 ) to provide theaforedescribed graphic display. Although, the system is capable ofcontinuous pressure and temperature monitoring, it can also be adaptedif desired for periodic monitoring so the pressure and/or temperaturereadings can be taken at intervals or on demand by the clinician. In allother respects, catheter 100 is identical to catheter 60 and thereforefor brevity further discussion is not provided since the structure andfunction of the balloons, the continuous pressure monitoring, etc., aswell as the aforedescribed alternative arrangements of catheter 60, arefully applicable to the catheter 100.

FIGS. 13A and 13B illustrate an alternate embodiment wherein catheter110 includes a pressure sensor within the balloon. More specifically,catheter 110 has an elongated flexible shaft 112 having a lumen(channel) 114 extending within the shaft 112 and communicating at itsdistal region with balloon 116 to fluidly communicate with balloon 116to inflate the balloon. Balloon 116 (also referred to as the pressureballoon) is utilized for monitoring pressure. A fluid side port 115 ispositioned at a proximal region 117 of the catheter 110 forcommunication with an infusion source for infusion of gas through thelumen 114 and into the balloon 116. The shaft 112 also includes a secondlumen (channel) 120 and third lumen (channel) 122 extending therein.Second lumen 120 has a side opening 124 at a distal portioncommunicating with the bladder. The third lumen 122 communicates at adistal region with stabilizing balloon 126 to fluidly communicate withballoon 126 to inflate the balloon to limit movement of the catheter 110to keep it in place within the bladder for drainage. A fluid port 113 ispositioned at a proximal region 117 of the catheter 110 forcommunication with an infusion source for infusion of fluid through thelumen 122 and into the balloon 126.

The pressure sensor 130 is carried by catheter 110 and positioned withinthe balloon 116 to measure pressure in response to deformation of theballoon in response to pressure exerted on an outer wall of balloon 116.The pressure transducer can include the sensor 130 or can be a separatecomponent positioned at a proximal end of the catheter external of thecatheter 110. The temperature sensor 132 can be positioned within theballoon 116, can be part of sensor 130, or alternatively positionedwithin lumen 114 (as shown in FIG. 13B), with its transmission wire(s)127 extending within the gas, e.g., air, lumen 114 along with the wiresof sensor 130 in the same manner as in catheter 60 described above.

In all other respects, catheter 110 is identical to catheter 60 andtherefore for brevity further discussion is not provided since thestructure and function of the balloons, lumens, continuous pressuremonitoring, etc. as well as the aforedescribed alternative arrangementsof catheter 60, are fully applicable to the catheter 110.

As discussed above, the pressure balloons disclosed herein have a largecircumferential area (and large volume) to provide multiple referencepoints for pressure readings and to provide an average pressure toenable more accurate readings. Thus, the pressure balloon provides forgross measurement. In an alternate embodiment shown in FIG. 15 , thepressure balloon for detecting pressure, designated by reference numeral142, forms an outer balloon of catheter 140. Contained within the outerballoon 142 is an inner balloon 143. The inner balloon 143 provides asmaller diameter balloon and a smaller circumference (and volume) thanthe outer balloon 14. The inner balloon 143 together with the lumen 144forms a smaller gas, e.g., air, column than in the embodiments discussedabove where the larger balloon internal space communicates directly withthe air lumen. This provides finer measurements. Thus, the compliantouter balloon 142 compresses the compliant inner balloon 143 whichcompresses the air within air lumen 144. The closed system is therebyformed by the internal space of the inner balloon 143 and the lumen 144.In certain instances, the smaller balloon air column can provide a moreaccurate reading from the average pressure determined by the largerouter balloon 142. Several embodiments of the inner/outer balloonarrangement are discussed herein.

The inner balloon 143 and outer balloon 142 can beseparately/independently inflated and closed with respect to each otherso there is no communication, e.g. passage of gas or liquid, between theinner and outer balloons 143, 142.

In the embodiments disclosed herein having inner and outer balloons, theouter balloon acts a medium of transmission to the inner pressureballoon. That is, as the outer balloon is deformed, the fluid within theouter balloon acts against the outer wall of the inner balloon to deformthe inner balloon and pressurize the gas, e.g., air, within the chamberof the inner balloon for pressure measurement. With the outer balloonfunctioning as a transmission medium, the bladder (or other body cavityin which the catheter is inserted) does not need to be filled withfluid. Thus, the catheter can be used in a voided cavity, e.g., withoutinterstitial fluid. The radial spacing between the wall of the outerballoon and wall of the inner balloon provides space for transmission ofthe fluid within the outer balloon to deform the inner balloon. Thespacing can be achieved in various ways which are described below andinclude for example, radial separation, a chamber interposed between theinner and outer balloons, a wall of the catheter interposed between theinner and outer balloons, etc. The advantages of not requiring insertionof fluid during pressure measurement are discussed below.

The pressure transducer and pressure sensor 150 can be positioned withinthe lumen 144 in the same manner as sensor 30 of FIG. 1 and can functionin the same manner. Alternatively, the pressure transducer can be at aproximal end of the catheter 140 as in the embodiment of FIG. 12 orexternal of the catheter. A temperature sensor can be part of sensor 150as in the embodiment of FIG. 1 or alternatively it can be a separatecomponent which can be positioned for example distal of the pressuresensor within the gas, i.e., air, lumen as in the embodiment of FIG. 8A.The transmission wires of the pressure sensor 150 and the temperaturesensor extend through lumen 144 or alternatively positioned in aseparate lumen.

The catheter 140 can optionally include a stabilizing balloon 145similar to balloon 76 of FIG. 8 . The catheter 140 would have a lumen,e.g., lumen 146, to inflate the stabilizing balloon 145. Lumen 148 withside opening 149 provides for drainage of the bladder. Lumen 144 whichis used to inflate the inner balloon 143 and create the gas column hasan opening at a distal region to communicate with inner balloon 143. Aseparate lumen 147 has an opening at a distal region to communicate withthe outer balloon 142 to fill the outer balloon 142.

In use, catheter 140 is inserted into the bladder and stabilizingballoon 145 is inflated to secure the catheter 140 in place. The systemis charged by inflation of the inner balloon 143, i.e., preferablypartially inflated for the reasons discussed above, by insertion of airthrough a side port which is in fluid communication with lumen 144 in aclosed system formed by the internal space 143 a of the inner balloon143 and the internal lumen 144 communicating with the internal space ofinner balloon 143. Outer balloon 142 is filled, i.e., preferablypartially inflated for the reasons discussed above, via injection of airthrough a separate lumen. With the outer balloon 142 inflated, pressuremonitoring can commence as external pressure applied to the largercircumferential outer surface of the outer balloon 142 compresses anddeforms the outer balloon 142 which compresses the inner balloon 143 asfluid presses the outer wall of the inner balloon. As the inner balloon143 is compressed and deformed in response to compression/deformation ofthe outer balloon 142 based on changes to bladder pressure, the sensor150 at the distal end of lumen 144 provides continuous pressurereadings, converted to an electrical signal by the transducer within thedistal end of lumen 144, and then electrically communicates throughwires 152 extending through lumen 144 to an external monitor eitherdirectly or via a converter. Although, the system is capable ofcontinuous pressure and continuous temperature monitoring, as in theother embodiments disclosed herein it can also be adapted if desired forperiodic monitoring so the pressure and/or temperature readings can betaken at intervals or on demand by the clinician. Note fluid does notneed to be present in the cavity to achieve the pressure readings.

Note that although separate lumens are provided for the inflation ofinner balloon 143 and outer balloon 142, in an alternate embodiment, asingle lumen can be utilized to inflate both balloons 143 and 142.

FIG. 16 illustrates an alternate embodiment of catheter 140, designatedby reference numeral 140′. Catheter 140′ is identical to catheter 140except a larger outer balloon 142′ is provided to cover more surfacearea for pressure readings. In all other respects, catheter 140′ isidentical to catheter 140 and for brevity further discussion is notprovided since the features and functions of catheter 140, and itsalternatives such as single or two lumens for inner and outer ballooninflation, are fully applicable to catheter 140′. For ease ofunderstanding, the components of catheter 140′ which are identical tocatheter 140 are given the same reference numerals as catheter 140.

Note that the larger balloon 142′ can be used with the catheters of anyof the embodiments described herein. Thus, a pressure balloon of thelarger size balloon 142′ can be used instead of the smaller pressureballoons illustrated in the drawings. Note the size of the balloons isprovided by way of example and are not necessarily drawn to scalecomparatively to the other components.

FIG. 17A illustrates an alternate embodiment of catheter 140, designatedby reference numeral 140″. Catheter 140″ is identical to catheter 140except a pear shaped larger outer balloon 142″ is provided. The largerballoon 142″ covers more surface area for pressure readings. The pearshape could in certain applications decrease the risk of obstructing theureter and provide more tactile continuity of the balloon to the bladderwall giving a better transmission of abdominal pressure to the internalsensor. In all other respects, catheter 140″ is identical to catheter140 and for brevity further discussion is not provided since thefeatures and functions of catheter 140, and its alternatives such assingle or two lumens for inner and outer balloon inflation, are fullyapplicable to catheter 140″. For ease of understanding, the componentsof catheter 140″ which are identical to catheter 140 are given the samereference numerals as catheter 140. FIG. 17B illustrates a catheteridentical to catheter 140″ with identical balloons, the only differencebeing that the side opening 149′ is positioned proximal of the balloon143 rather than distal of the balloon as in FIG. 17A. That is, opening149′, in communication with the catheter lumen 148′ for drainage of thebladder, is positioned between the stabilizing balloon 145 and the outerpressure (and inner) pressure balloon 142″ (and 143). Thus, it is distalof the stabilizing balloon 145 and proximal of the outer balloon 142″.

Note that the positioning of the side opening for drainage of FIG. 17B,which communicates with the drainage lumen of the catheter, can beutilized with any of the catheters disclosed herein. Thus, in thecatheters disclosed in the various embodiments herein, instead of thedrainage opening positioned distal of the pressure balloon(s), it can beproximal of the pressure balloon and distal of the stabilizing balloonso it is between the two balloons.

Note that the pear shaped balloon 142″ can be used with the catheters ofany of the embodiments described herein. Thus, a pressure balloon of thepear shape of balloon 142″, and of larger or smaller size if desirable,can be used instead of the pressure balloons illustrated in thedrawings.

FIGS. 18-25B illustrate an alternate embodiment of the catheter of thepresent invention. The pressure balloon for detecting pressure,designated by reference numeral 202, forms an outer balloon of catheter200. Contained within the outer balloon 202 is an inner balloon 204. Theinner balloon 204 provides a smaller diameter balloon and a smallercircumference (and volume) than the outer balloon 202. The inner balloon204 together with the lumen 214, which communicates with the innerballoon 204 for inflation thereof, forms a smaller gas, e.g., air,column as in the embodiments of FIGS. 15-17 . This provides finermeasurements. Thus, the compliant outer balloon 202 fluid or wallcompresses the outer wall 205 of the compliant inner balloon 204 whichcompresses the air (or other gas) within air lumen 214. The closedsystem is thereby formed by the internal space 204 a of the innerballoon 204 and the lumen 214. The smaller balloon air column can incertain instances provide a more accurate reading from the averagepressure determined by the larger outer balloon 202.

The pressure transducer and pressure sensor are external to catheter 200and mounted to port 218 at the proximal end 201 of catheter 200. Morespecifically, a transducer hub or housing, designated generally byreference numeral 240, contains the sensor and pressure transducer andis mounted to the angled side port 218. In the embodiment of FIG. 18A,the hub 240 is mounted over the port 218 and can be locked or securedthereto such as by a friction fit, snap fit, threaded attachment, alatch, etc., maintaining an airtight seal so the air is contained withinthe lumen 214 and balloon 204. The hub 240 has an elongated (rod-like)member or nose 242 extending distally therefrom (FIG. 24A) dimensionedto be inserted through the proximal opening in port 218 and into airlumen 214. (Note the air lumen 214 as in the other lumens extend intotheir respective angled side ports). The elongated member 242 also has achannel 244 extending therethrough to allow the pressure wave to travelthrough to the pressure sensor. Although in preferred embodiments noadditional air needs to be injected into inner balloon 204 via lumen 214after attachment of hub 240, it is also contemplated that a port oropening can be provided in hub 240 to receive an injection device forinjection of additional air. Such additional air can communicate withand flow through channel 244 of elongated member 242, into lumen 214 andinto inner balloon 204 for inflation, or alternatively, a side port oropening in angled port downstream of the elongated member 242 could beprovided.

To charge the system, when the hub 240 is mounted to the side port 218,the elongated member 242 extends into lumen 214 to advance air throughthe air lumen 214 into inner balloon 204 to expand inner balloon 204. Insome embodiments, 0.2 cc of air can be displaced/advanced by the member242, although other volumes are also contemplated. Thus, as can beappreciated, mounting of the hub 240 to the catheter 200 automaticallypressurizes the air lumen/chamber and expands the inner balloon 204.Note the inner balloon 204 can be partially or fully inflated(expanded), dependent on the amount of air advanced into the innerballoon 204. Further note that the lumen 214 is not vented to atmospherewhen the transducer hub 240 is attached and air is advanced through theair lumen. The port 218 can include a closable seal through which theelongated member 242 is inserted but maintains the seal when theelongated member 242 remains in the lumen 214. This maintains a closedsystem.

Lumen 214 which is used to inflate the inner balloon 204 and create theair column has an opening at a distal region to communicate with theinterior of inner balloon 204. Lumen 212 of catheter 200 has an openingat a distal region to communicate with the outer balloon 202 to fill theouter balloon 202. Angled port (extension) 222 at the proximal end ofcatheter 200 receives an inflation device to inflate, either fully orpartially, the outer balloon 202.

Note as in the other embodiments disclosed herein, air is described asthe preferred gas for creating the column and expanding the balloon,however, other gasses are also contemplated, for each of the embodimentsherein.

The outer balloon 202 can be shaped such that a distal region 207 a(FIGS. 20A-20C) has an outer transverse cross-sectional dimension, e.g.,diameter, greater than an outer transverse cross-sectional dimension,e.g., diameter, of the proximal region 207 b. A smooth transition(taper) can be provided between the distal region 207 a and proximalregion 207 b. Note the balloon 202 can be pear shaped as shown in FIGS.20B and 20C although other configurations are also contemplated. Thispear shape in some applications is designed to conform to the shape ofthe bladder.

The inner and outer balloons 204, 202 can by way of example be made ofurethane, although other materials are also contemplated such assilicone or EVA.

A temperature sensor 230 (FIG. 18B), such as a thermocouple, ispositioned within the catheter 200 at a distal end to measure core bodytemperature. The sensor 230 is shown positioned in a lumen 216 separatefrom the lumens 214 and 212. One or more wires 232 extend from thesensor 230 through the lumen 216, exiting the lumen 216 and catheter 200at a proximal end between the angled extensions/ports of the catheter200, e.g., between the port 218 for the inner balloon 204 and the port222 for the outer balloon 202. A connector 234, e.g., a male connector,is at the proximal terminal end of the wire 232 as shown in FIG. 25B.The transducer hub 240 includes a connector 247 with openings 249 (FIG.25A) which receive the connector 234 of the wire 232. When the hub 240is mounted to port 218 of catheter 200, the connector 234 of the wire isautomatically connected to a connector carried by or within the hub 240which is in communication with a temperature monitor. Note theconnector, e.g., female connector, within or carried by the hub 240 canalready be mounted to an external temperature monitor via a cable whenthe hub 240 is mounted to catheter 218 or alternatively the hub 240 canfirst be mounted to port 218 of the catheter 200 and then a cable isconnected between the temperature monitor and catheter 200. In theillustrated embodiment of FIG. 25A, the wire connector 234 can plug intothe openings 249 of connector 247 positioned on the hub 240. Note theconnector 247 can also be internal of the hub 240 with an opening in thewall of the hub to enable access for the wire connector. Also note thatalternatively the wire can include a female connector and the hub canhave a male connector. Other types of connectors/connections are alsocontemplated.

As can be appreciated, connection of the transducer hub 240 to thecatheter 200 (port 218) a) automatically connects the temperature sensor230 to a connector for communication with a temperature monitor cable;and b) automatically advances air through the first lumen 214 to expandthe inner balloon 204.

The catheter 200 can optionally include a stabilizing balloon 206similar to balloon 76 of FIG. 8A. The stabilizing balloon 206 can bemade of silicone, although other materials are also contemplated. Ifprovided, the catheter 200 would have a lumen, e.g., lumen 210, toinflate the stabilizing balloon 206. Angled side port 217 can beprovided in communication with lumen 210 for injection of a liquid orgas to expand the stabilizing balloon 206. The foregoing description ofthe stabilizing balloons in connection with other embodiments is fullyapplicable to balloon 206. Catheter 200 also includes a lumen 211 with adistal side opening 211 a (FIG. 18B) to provide for drainage of thebladder as in the aforedescribed embodiments. In the illustratedembodiment, the side opening 211 a is distal of outer balloon 202 andinner balloon 204 and distal of the stabilizing balloon 210 which asshown is proximal of outer balloon 202 and inner balloon 204. Inalternate embodiments, the side opening for drainage could be proximalof the inner and outer balloons. In alternate embodiments, thestabilizing balloon 206 can be distal of the outer balloon 202.

In the embodiment of FIG. 18A, catheter 200 has five lumens: 1) lumen214 communicating with inner balloon 204 to inflate the inner balloon204 and forming the air filled chamber; 2) lumen 212 communicating withouter balloon 202 for inflating outer balloon 202; 3) lumen 210communicating with the stabilizing balloon 206 to inflate stabilizingballoon 206; 4) drainage lumen 211 having a side opening 211 a at adistal end for drainage of the bladder; and 5) lumen 216 for thetemperature sensor wire(s) 232. (Note in alternate embodiments, thetemperature sensor wires could be located in the lumen 214 so thecatheter would not have the additional lumen 216) Catheter 200 also hasthree angled extensions/ports at its proximal end 201: 1) port 218 foraccess to lumen 214 to inflate the inner balloon 204; 2) port 222 foraccess to lumen 212 to inflate outer balloon 202; and 3) port 217 foraccess to lumen 210 to inflate stabilizing balloon 206. Drainage lumen211 extends linearly terminating at region 223. Lumen 216 terminatesproximally at the region of the angled ports 218, 222 through which wire232 can exit from the catheter 200 for connection to a temperaturemonitor via hub 240. Note the location of the ports can vary from thatillustrated in FIG. 18 . Also, location of the lumens and thecross-sectional dimension and size of the lumen can vary from that shownin FIG. 23 as FIG. 23 provides just one example of the location andsize, e.g., diameter, of the lumens as well as the shape/cross-sectionalconfiguration and location. The catheter 200, as in the foregoingembodiments, can have an atraumatic tip 209.

In use, catheter 200 is inserted into the bladder and stabilizingballoon 206 is inflated to secure the catheter 200 in place. The systemis charged by inflation of the inner balloon 204, i.e., preferablypartially inflated for the reasons discussed above, by advancement ofair through lumen 214 upon attachment of the pressure transducer 240 tothe port 218 of catheter 200. Such attachment moves elongated member 242into lumen 214 to displace the air (or other gas) already in the lumen214 to expand the inner balloon 204. A closed system is formed by theinternal space 204 a of the inner balloon 204 and the internal lumen 214communicating with the internal space 204 a of inner balloon 204. In apreferred embodiment, additional air does not need to be added to theballoon 204/lumen 214. Outer balloon 202 is filled, i.e., preferablypartially inflated for the reasons discussed above, via injection of airthrough the separate port 222 which communicates with lumen 212 ofcatheter 200. With the outer balloon 202 inflated, pressure monitoringcan commence as external pressure applied to the larger circumferentialouter surface of the outer balloon 202 compresses and deforms the outerballoon 202 which exerts a force on the outer wall of inner balloon 204(via fluid contact with the outer wall of the inner balloon) andcompresses the inner balloon 204. As the inner balloon 204 is compressedand deformed in response to compression/deformation of the outer balloon202 based on changes to bladder pressure, the pressure sensor within theexternal hub 240 attached at the proximal end of the catheter 200provides continuous pressure readings, converted to an electrical signalby the transducer of the sensor within the hub 240, and thenelectrically communicates through a connector, e.g. cable 245, to anexternal monitor either directly or via a converter to display pressurereadings. Although, the system is capable of continuous pressure andcontinuous temperature monitoring, it can also be adapted if desired forperiodic monitoring so the pressure and/or temperature readings can betaken at intervals or on demand by the clinician. Temperature readingsare also taken during the procedure as temperature sensor 230 isconnected to a temperature monitor via wire 232 connected to a connectorof hub 240 which is connected to the temperature monitor to displaytemperatures. The temperature monitor can be separate from the pressuredisplay monitor or alternatively integrated into one monitor. Cable 245can connect to the temperature monitor as well (directly or via aconverter) or a separate cable extending from the hub 240 could beprovided for connection to the temperature monitor.

Note that although separate lumens are provided for the inflation ofinner balloon 202 and outer balloon 204, in an alternate embodiment, asingle lumen can be utilized to inflate both balloons 202 and 204. Insuch embodiment, catheter 200 can have one less angled port and one lesslumen since inflation of the outer balloon 202 would be through port 218and lumen 214.

The proximal and distal end of the inner balloon 204 in the illustratedembodiment are within the confines of the outer balloon 202, i.e., theproximal end of the inner balloon 204 is distal of the proximal end ofthe outer balloon 202 and the distal end of the inner balloon 204 isproximal of the distal end of the outer balloon 202. Thus, in thisillustrated embodiment, the inner balloon 204 is fully encapsulatedwithin the outer balloon 202.

With the inner/outer balloon arrangement, the larger outer surface ofthe outer balloon 202 takes gross measurements and then the forces areconcentrated on the smaller inner balloon 204 to amplify/concentratepressure on the small area of the inner balloon so small changes can bedetected and waves transmitted to the pressure transducer (via thelength of the lumen to a proximal transducer, e.g., an external pressuretransducer).

As noted above, preferably no additional air needs to be added aftermounting of hub 240. However, it is also contemplated that in alternateembodiments a port can be provided in communication with hub 240 toenable subsequent injection of air though lumen 214 and into innerballoon 204. Additionally, outer balloon 202 can in some embodimentsreceive additional fluid injection via port 222 during the procedure.

FIGS. 30A-34 illustrate an alternate embodiment of the catheter,designated generally by reference numeral 400. The catheter 400 differsfrom catheter 200 of FIG. 18A in the attachment of the inner and outerballoons to the catheter shaft. The catheter 400 also differs catheter200 described above in the location of the drainage hole(s). In allother respects catheter 400 is the same as catheter 200 and thus thefeatures and functions of catheter 200, and its alternatives disclosedherein, are fully applicable to catheter 400.

Catheter 400 has a shaft 402 having a distal region (portion) 402 aterminating in a distal opening 402 b. Distal opening 402 b receivescore pin 410 therein. Core pin 410, also referred to as a bonding pin ora connecting pin, has a proximal end 414 a dimensioned for insertion ina press fit through opening 402 b and into the lumen in distal region402 a of shaft 402. In the illustrated embodiment, the proximal end 414a has a non-circular shape, e.g., a triple lobe or Y shape,corresponding to the shape of the opening 402 b. The distal end of thepin 410 has a reduced diameter cylindrical portion 414 b which receivesthereover a distal tip 412 (also referred to herein as a distal plug).

Catheter 400 further has a retention (stabilizing) balloon 404, an innerballoon 408 and an outer balloon 406. The retention balloon 404 isspaced proximally of the outer balloon 406 and inner balloon 408. Theouter balloon 406 encapsulates the inner balloon 408 such that the innerwall 408 c of the inner balloon 408 is contained within the outerballoon 406. The outer wall 406 c of outer balloon 40 c is exposed tothe patient, e.g., the bladder. The retention balloon 404 functions inthe same way as the retention (stabilizing) balloons described above andcan be of varying shapes as described herein. The inner and outerballoons 408, 406 function in the same way as the inner and outerballoons 204, 202 of catheter 200.

As shown in the cross-sectional view of FIG. 30C, the catheter shaft 402has four lumens: 1) lumen 438 communicating with inner balloon 408 toinflate the inner balloon 408 and forming the gas, e.g., air, filledchamber; 2) lumen 434 communicating with outer balloon 406 for inflatingouter balloon 406; 3) lumen 436 communicating with the retention balloon404 to inflate retention balloon 404; and 4) drainage lumen 432 havingone or more side openings 418 (FIG. 32C) at a distal region of thecatheter for drainage of the bladder. The lumens 438, 434 and 436terminate inside of their respective balloons 402, 406 and 404. The sideopening(s) 418 for drainage are positioned between the outer/innerballoon 406, 408 and the retention balloon 404 such that the outerballoon 406 and inner balloon 408 are distal of the side opening(s) 418and the retention balloon 404 is proximal of the side opening(s) 418.Temperature sensor wires can be positioned in lumen 438, runningparallel to the tubular portion (described below) of the inner balloonin embodiments where the balloon has the tubular portion, e.g., balloon458, with the thermistor sensor located near the drainage holes 418. Thetemperature sensor wires can be positioned in the same lumen as thelumen for filling the outer balloon or the inner balloon or anadditional lumen can be provided for the temperature sensor wire(s).

Catheter 400 also has three angled extensions/ports at its proximal end420 (FIG. 30B): 1) port 428 for access to lumen 438 to inflate the innerballoon 408; 2) port 426 for access to lumen 434 to inflate outerballoon 406; and 3) port 422 for access to lumen 436 to inflatestabilizing balloon 404. Drainage lumen 432 extends linearly terminatingat a distal region proximal of core pin 410 and terminating proximallyat port 424. Note the location of the ports can vary from thatillustrated in FIG. 30B. Also, the location of the lumens and thecross-sectional dimension and size of the lumens can vary from thatshown in FIG. 30C as FIG. 30C provides just one example of the locationand size, e.g., diameter, of the lumens as well as theshape/cross-sectional configuration and location.

The steps of manufacture (assembly) of the balloons to the catheter willnow be described with reference to FIGS. 32A-32C. The assembly steps areshown with the balloons inflated for ease of illustration but theassembly would preferably be made with the balloons deflated. Inmanufacture, the stabilizing balloon 404, which is identical in functionand can be the same shape as the stabilizing (retention) balloonsdiscussed above, such as a donut shape as shown, is placed over theouter shaft 402 and proximal and distal extensions 404 a, 404 b ofballoon 404 are attached, e.g., welded to the shaft 402. In theillustrated embodiment, the stabilizing balloon 404 is composed of thesame material as the distal region 402 a of shaft 402. In one embodimentby way of example, the material is silicone, although other materialsare also contemplated. After the stabilizing balloon 404 is placed overthe shaft 402, positioned proximal of the distal end of the shaft 402,and preferably after it is also attached to the shaft 402, the bondingpin 410 is inserted into the shaft 402. More specifically, proximalextension 414 a extends into distal opening 402 b of shaft 402, with aportion of the pin 410 including the distal extension 414 b extendingdistally from and exposed from the shaft 402 as shown in FIG. 32A. Thebonding pin 410 is preferably mechanically fixed, such as by a press fitinto the lumen of the shaft 402. The shaft 402 contains small holesoverlying the inserted pin 410 and the small holes are filled withmaterial, e.g., silicone, to secure the pin 410 to the shaft 402.

Next, with reference to FIG. 32B, the inner balloon 408 is placed overthe bonding pin 410 and proximal and distal extensions 408 a, 408 b areattached, e.g., welded, to the bonding pin 410. The balloon 408 isattached to the center cylindrical region of the pin 410, leaving theproximal and distal extensions 414 a, 414 b exposed. In the illustratedembodiment, the inner balloon 408 is composed of the same material asthe bonding pin 410 and both the bonding pin 410 and inner balloon 408are composed of a different material than the distal region 402 a of theshaft 402. (The distal region 402 a can be the same material as theremainder or other portions of the shaft 402 or composed of a differentmaterial). After placement of the inner balloon 408 over the bonding pin410, and either before or after attachment (e.g., welding) of the innerballoon 408 to the pin 410, distal tip or plug 412 is placed over distalextension 414 b of pin 410 (FIG. 32C). Distal tip 412 has an opening 416to receive extension 414 b and is mechanically fixed, e.g., by a pressfit, to the pin extension 414 b. As shown, the tip 412 is spaceddistally from the inner balloon 408. The tip 412 in some embodiments iscomposed of a different material than the core pin 410 and is preferablycomposed of the same material as the outer balloon 406, e.g., silicone,although other materials can be utilized. FIG. 32D illustrates the nextstep in assembly as the outer balloon 406 is inserted over the distaltip 412 and over the inner balloon 408 and bonded at a proximalextension 406 a to the outer shaft 402 and at the distal extension 406 bto the tip 412. Thus, as can be appreciated, in this embodiment, theouter balloon 406 is bonded at both ends to structure composed of thesame material as the outer balloon 406; and the inner balloon 408 isbonded at both ends to structure composed of the same material as theinner balloon 408. Also, the retention balloon 404 is bonded at bothends to structure composed of the same material as the retention balloon404. In other words, as can be appreciated, the embodiment of FIGS.31-34 enables inner and outer balloons of different materials to beattached to the shaft of the catheter, e.g., materials that do not bond.Additionally, or alternatively, it enables a balloon of a differentmaterial than the shaft to be attached to the shaft. In one embodimentby way of example, the shaft is composed of silicone, the inner balloonis composed of EVA and the outer balloon is composed of silicone so EVAis bonded to EVA and silicone is bonded to silicone. In such embodiment,the core pin by way of example is composed of EVA. It should beappreciated that these materials are provided by way of example as othermaterials are also contemplated.

In some embodiments, the outer balloon 406 is folded over itself asshown in FIG. 34 to allow the balloon 406 when inflated to extend outand fully cover the distal tip 412. Thus, the outer balloon 406 in itsdeflated condition has a distal cuff 411 which exposes the distal tip412 for atraumatic insertion of the catheter 400, and expands to coverthe distal tip 412 when inflated when the catheter 400 is fully insertedand placed at the target location. The balloons 404, 406 and 408 can beof the various shapes of the stabilizing, outer and inner balloonsdisclosed herein. In FIGS. 30A to 34 the outer balloon 406 by way ofexample is shown as pear shaped.

FIGS. 30A-34 illustrate the fully assembled catheter 400 which is usedto measure pressure in the same manner as catheter 200 of FIG. 18A.Thus, a transducer hub 430, which can be any of the transducer hubsdisclosed herein, such as hub 240 of FIG. 24A, hub 300 of FIG. 28A,etc., is attached to port 420 to advance gas, e.g., air through thelumen to inflate inner balloon 408. The lumens 438, 434 for inflation ofthe inner balloon 408 and outer balloon 406 are radially spaced fromcore pin 410 as core pin occupies the drainage lumen 432 (distal of sideopenings 418) and does not interfere with the balloon inflation lumens434, 438.

Side opening(s) 418 in catheter 400 communicate with the drainage lumen432 for draining the bladder. As shown, the drainage opening(s) 418 inthis embodiment is positioned between the a) outer balloon 406/innerballoon 408 and b) retention balloon 404. More than one drainage openingcan be provided. It should be appreciated that such location of thedrainage opening(s) between the retention balloon and pressureballoon(s), rather than distal of the pressure balloon(s) can beutilized with any of the catheter embodiments disclosed herein.

As noted herein, the catheters of the present invention can be utilizedfor measuring other pressure in a patient and are not limited tointra-abdominal pressure nor limited to measuring bladder pressure.

In the foregoing embodiments, the inner balloon is positioned within theouter balloon (with its outer wall radially spaced from the outer wallof the outer balloon) and deformation of the outer balloon based onchanges in pressure within the patient, e.g., within the bladder inresponse to abdominal pressure, causes deformation of the inner balloonas the fluid within the outer balloon (or wall) exerts a pressureagainst the wall of the inner balloon. This deforms the inner balloon toprovide a pressure reading. In the alternate embodiment of FIGS. 35-41 ,the inner balloon is positioned within a chamber (or cage). This chamberforms an inner balloon encapsulating member as it encircles/encapsulatesthe inner balloon and is positioned between the inner balloon and outerballoon. Thus, the encapsulating member (chamber) separates the outerwall of the inner balloon from the interior of the outer balloon.However, the chamber has a series of openings so that the fluid withinthe outer balloon can pass through the chamber and apply a pressureagainst the outer wall of the inner balloon to deform the inner balloonto provide pressure readings in the same manner as the other embodimentsdisclosed herein. As in other outer/inner balloon embodiments, thecatheter can be used is a voided cavity, e.g. a voided bladder, sincefluid, e.g., water, does not need to be injected since the fluid withinthe outer balloon acts as a transmission medium.

With reference now to FIGS. 35-41 , the catheter 450 has an elongatedshaft 451. Note only the distal end of the catheter 450 is shown; theproximal end, hub, connector, etc. being the same as in the foregoinginner and outer balloon embodiments, e.g., catheter 200 of FIG. 18A. Thecatheter 450 has a retention balloon 454 identical to retention(stabilizing) balloon 206 of catheter 200 (or other stabilizing balloonsdisclosed herein), an inner balloon 458 and an outer balloon 456. In thegap (space) between the proximal end of the outer balloon 458 and thedistal end of the retention balloon 454, is a drainage hole 463 (ormultiple drainage holes) for draining the cavity, e.g., the bladder. Athermistor can be placed adjacent the drainage opening 463 fortemperature readings, and the thermistor wire can extend through a lumenof the catheter 450, e.g., the drainage lumen, the pressure lumen or aseparate lumen, for electrical connection to a temperature monitor.Catheter 450 has three lumens: 1) lumen 486 communicating with outerballoon 456 for inflating outer balloon 456; 2) a lumen communicatingwith the retention balloon 454 to inflate retention balloon 454; and 3)drainage lumen 484 having one or more side openings 463 at a distalregion of the catheter for drainage of the bladder. In this embodiment,the tubular portion of the inner balloon 458 is positioned within thedrainage lumen. In an alternate embodiment such as the embodiment ofFIGS. 42-46 discussed below, a separate lumen can be provided to receivethe tubular portion of the inner balloon.

The outer balloon 456 has a proximal end 456 a attached to the shaft 451and a distal end 456 b attached to the chamber 452. The outer balloon456 can include a cuff 457 like cuff 411 of outer balloon 406 of FIG. 34wherein it is folded over itself to expose the atraumatic tip 460 of thecatheter 450 (the atraumatic tip of the chamber 452 or catheter) andwhen expanded covers the tip 460. In one embodiment, the spacing betweenthe proximal end of the outer balloon 456 and the distal end of theretention balloon 454 is about 20 cm but other spacings/distances arealso contemplated.

The chamber 452 forms the distal end region of the catheter 450 as itextends distally from the distal edge 451 a of shaft 451. With referenceto FIGS. 37 and 38 , chamber 452 has a reduced diameter proximalextension 464 for press fit and attachment within the distal end ofshaft 451. Opening 466 in chamber 452 communicates with lumen 467 whichextends through proximal extension 464, terminating at cavity 452 a ofchamber 452. Opening 468 lines up with outer balloon inflation channelfor inflating the outer balloon. Chamber 452 has a wall 472 forming ashoulder for abutment with distal wall 459 of shaft 451 (see FIG. 40 ).Cavity 452 a is dimensioned to receive the inner balloon 458 in thedeflated condition as well as in the inflated condition. As shown inFIG. 40 , in the inflated condition, a small gap 473 exists between theouter wall 458 b of the inner balloon 458 and the inner wall 474 of thechamber 452. In some embodiments, the gap is about 0.020 inches,although other sized gaps (spacing) are also contemplated. Cavity 452 aterminates distally at wall 469. In some embodiments, a wire can extendthrough the inner balloon 458 and be embedded in wall 469 (pierces thewall 469) to help stabilize and center the inner balloon 458. Such wirecan extend proximally from wall 469, through cavity 452 a and throughlumen 467 and extend through a lumen in the catheter, extending throughthe entire, or alternatively, a partial, length of the catheter.

Chamber 452 also includes a plurality of openings 462 (only some ofwhich are labeled for clarity) to provide fluid (liquid or gas) flowfrom the outer balloon 456 against the outer wall 458 b of the innerballoon 458 retained within the chamber 452. Thus, the chamber 452separates the outer wall 458 b of the inner balloon 458 from theinterior of the outer balloon, except for the communication through theopenings 462 in the chamber 452. (The inner and outer balloons aresealed from each other so they are not in fluid communication with eachother). One arrangement of chamber openings is shown by way of examplein FIGS. 37 and 38 , with two rows of three longitudinally alignedopenings (holes) and two rows of two longitudinally aligned openings,each row spaced apart radially around the circumference of the chamber452. The rows are shown equidistantly spaced but other arrangements arealso contemplated. Also, a fewer or greater number of rows can beprovided and a different number of holes than the number shown can beprovided. Holes of different sizes than shown, as well as holes ofvarying size in the chamber 452, are also contemplated. The chamber 452can be made of silicone, although other materials are also contemplated.

The inner balloon 458 has balloon portion 459 a and a tube portion 459b. The balloon portion 459 a as referred to herein is the portion orregion that expands within the catheter (e.g., chamber) and is theregion that is within the outer balloon that receives fluid contact fromthe fluid in the outer balloon. The balloon portion 459 a has a largerdiameter than the tube portion 459 b as shown in FIG. 40 . The tube(tubular) portion 459 b extends through lumen 467 of chamber 452 andthrough lumen 484 in the catheter shaft 451. The tube portion 459 b canextend the entire length of the catheter 450 such that it terminatesadjacent the inflation port so that the enclosed gas chamber is formedby the tubular portion 459 b and balloon portion 459 a. Alternatively,the portion can terminate within the lumen 484 of the shaft 451 orwithin the lumen 467 of the chamber 452 in which case inflation fluid,e.g., gas such as air, would flow through the shaft lumen (and throughlumen 467 in the latter embodiment) for a certain length where it wouldthen enter an opening in the tubular portion 459 b for flow into theinner balloon 458. The inner balloon 458 can be made of polyamide suchas nylon, although other materials are also contemplated, such as EVA.The inner balloon 458 can be made of various dimensions, and in oneembodiment by way of example the full balloon diameter is about 3.5 mm,the balloon length is about 10 mm and the wall thickness is about 0.05mm. By way of example, the inner diameter tubular portion 459 b of theinner balloon 458 could be about 0.2 mm. Other balloon dimensions arealso contemplated. A wire could be provided to fill the gap to reducethe air column. The distal end of the inner balloon 458 can be welded orsoldered or sealed by other methods.

Note in the embodiments wherein the inner balloon has an elongatedtubular portion extending through the lumen of the catheter, the tubularportion can be integral with the enlarged region of the balloon thatreceives the fluid contact from the outer balloon. In alternativeembodiments, the tubular portion can be a separate component attached tothe balloon portion. In other embodiments, the tubular portion can be inthe form of a metal tube extending through the lumen of the catheter andattached to the tail of the inner balloon. In any of these versions, thetubular portion along with the balloon portion form the gas chamber. Insome embodiments, the tubular portion can extend through the entire oralmost the entire length of the lumen of the catheter and terminate atthe proximal end adjacent the distal end of the elongated member (rod)of the hub used to inflate the inner balloon. In other embodiments, itcan terminate more distal.

A sealant or plug 480 can be provided, the plug 480 positioned aroundthe tubular portion 459 b of the inner balloon 458 which closes off thelumen 467 distal of the drainage hole 463. The plug 480 could also helpmaintain the centering of the tubular portion 459 b. Plug 480 abutsinner wall 478 of chamber 452 as shown in FIG. 40 . The plug in oneembodiment is made of RTV silicone.

A thermistor can be positioned adjacent the drainage opening(s) 463 andthe temperature sensor wires can be positioned in lumen 484, runningparallel to the balloon tubular portion 459 b. Alternatively, thetemperature sensor wires can be positioned in the same lumen as thelumen for filling the outer balloon or alternatively an additional lumencan be provided for the temperature sensor wire(s).

The outer balloon 456 could include a coating such a parylene to changethe modulus of the balloon. That is, such coating could stiffen theballoon so it is not to continuously expanding under pressure, whichcould cause a reduced pressure reading. The coating can also cover allor part of the catheter which could add lubricity.

The inner and outer balloons disclosed herein can be filled to variousvolumes. In one example, the inner balloon can be filled to a volume ofabout 0.16 cc and the outer balloon can be filed to about 10 cc.

The inner and outer balloons disclosed in the various embodiments can becoated to reduce their permeability. That is, to prevent escape of air,the balloons can be made of an impermeable material and/or the balloonscan be made of a permeable material and coated with an impermeablematerial. As used herein, impermeability means there is no (ornegligible) pressure decay in the balloon over a period of time in whichthe catheter remains inserted into the body. This period of time couldbe for example from one day to up to 30 days. This period of time ofcatheter insertion, due to current hospital and clinical protocols,typically does not exceed 30 days, but impermeability of the balloons ofthe present invention can also mean little or no leakage for a longerperiod of time, e.g., 45 days, depending on the protocol for duration ofcatheter insertion.

Various features affect pressure decay which include the density of theballoon material, the material and/or structure of the balloon, and thetype and/or density of coating on the balloon. The catheters of thepresent invention provide pressure loss management by limiting loss ofpressure resulting from escape of air (or other gas) from the system.The pressure management, affected by these parameters, also needs to bebalanced with the size and patient comfort restraints, which thecatheters of the present invention achieve.

Additionally, the amount of dead space in the system can affect decaybecause if there is more gas (e.g., air) in the system, the percentageloss will have less of an overall effect than if there is less gas inthe system. However, a larger gas chamber acts as a dampening affect sothere is less responsiveness. Therefore, the catheters of the presentinvention achieve this balance of accurate pressure reading (due tomaximized responsiveness) while minimizing or eliminating pressure decayin the necessary time period.

Note that when used in the bladder, there is an osmotic effect withurine. That is, urine sucks out the air from the system as the pHchanges. The impermeability of the balloon helps to limit or eliminatethis osmotic effect.

As noted herein, the catheters of the present invention can be utilizedfor measuring other pressure in a patient and are not limited tointra-abdominal pressure nor limited to measuring bladder pressure.Thus, the double balloon/chamber structure of FIGS. 35-41 can be usedfor example with catheters to measure maternal uterine contractionpressure by measuring bladder pressure as in co-pending application Ser.No. 15/949,022, filed Apr. 9, 2018, the entire contents of which areincorporated herein by reference, and with catheters to measure theintrauterine pressure in the uterus and the fallopian tubes during HSG,SHG, HyCoSy, or SIS procedures or other procedures, as in co-pendingapplication Ser. No. 15/978,072, filed May 11, 2018, the entire contentsof which are incorporated herein by reference.

Catheter 450 can be used in the same manner as the catheters describedabove, and such aforedescribed use(s) are fully applicable to catheter450, the difference being the caged inner balloon. Thus in use, catheter450 is inserted into the cavity, e.g., bladder, and stabilizing balloon454 is inflated to secure the catheter 450 in place. The system ischarged by inflation of the inner balloon 458, i.e., preferablypartially inflated for the reasons discussed above, by insertion of airthrough a side port which is in fluid communication with tubular portion459 b, or by mounting of the transducer hub as described herein, in aclosed system formed by the internal space of the inner balloon 458 andthe internal catheter lumen and/or tubular portion 459 b communicatingwith the internal space of inner balloon 458. Outer balloon 456 isfilled, i.e., preferably partially inflated for the reasons discussedabove, via injection of fluid such as air or saline through a separatelumen. With the outer balloon 456 inflated, pressure monitoring cancommence as external pressure applied to the larger circumferentialouter surface of the outer balloon 456 compresses and deforms the outerballoon 456 which forces fluid within the outer balloon 456 throughopenings 462 in chamber 452 against the outer wall of the inner balloon458, compressing the inner balloon 458. As the inner balloon 458 iscompressed and deformed in response to compression/deformation of theouter balloon 456 based on changes to bladder pressure, the sensorprovides continuous pressure readings, communicated to an externalmonitor. Although, the system is capable of continuous pressure andcontinuous temperature monitoring, as in the other embodiments disclosedherein it can also be adapted if desired for periodic monitoring so thepressure and/or temperature readings can be taken at intervals or ondemand by the clinician.

An alternate embodiment of the chamber (cage) is illustrated in FIGS.42-46B and designated by reference numeral 490. Chamber 490 differs fromchamber 452 in that it has a slot 496 for ease of assembly and has anangled channel 503 for receipt of the tubular portion of the innerballoon. More specifically, elongated slot 496 extends through an outerwall of the chamber 490 and allows the inner balloon 510 to be placed,e.g. top loaded, into the cavity 496 of the chamber 490. The innerballoon 510 is identical to inner balloon 458 described above exceptthat the tubular portion 512 extending proximally from balloon portion511 is angled at portion 513 so that the tubular portion 512, ratherthan being placed in the drainage lumen as in FIG. 40 , is placed in aseparate lumen 522. Angled channel 503 in chamber 490 receives theangled portion 513 of balloon 510.

Like chamber 452, chamber 490 has a series of openings 494 to providefluid (liquid or gas) flow from the outer balloon 514 against the outerwall of the inner balloon 510 retained within the chamber 490. Thus, thechamber 490, like chamber 452, separates the outer wall of the innerballoon 510 from the interior of the outer balloon 514, except for thecommunication through the openings 494 in the chamber 490. Onearrangement of chamber openings is shown by way of example in FIG. 42 ,with one row of three openings (holes), however, other arrangements arealso contemplated. Also, a greater number of rows can be provided and adifferent number of holes than the number shown can be provided as wellas holes of different sizes than shown and holes of varying size. Thechamber 490 can be made of silicone, although other materials are alsocontemplated.

Chamber 490 has a reduced diameter proximal extension 502 for press fitand attachment within the distal end of the catheter shaft. Slot 504 inchamber 490 communicates, i.e., aligns, with lumen 528 for inflatingouter balloon 514. A wire can extend through the inner balloon 510 andbe embedded in a wall 493 (pierces the wall 493) to help stabilize andcenter the inner balloon 510.

The catheter has four lumens: 1) lumen 522 receiving the tubular portion512 of the inner balloon 510; 2) lumen 528 communicating with outerballoon 514 for inflating outer balloon 514; 3) lumen 525 communicatingwith the retention balloon 516 to inflate retention balloon 516; and 4)drainage lumen 524 having one or more side openings 520 at a distalregion of the catheter for drainage of the bladder. In this embodiment,the tubular portion 512 of the inner balloon 510 is positioned in aseparate lumen as shown. Except for the angled portion 513, the innerballoon 510 is identical to the inner balloon 458 of FIG. 41 . The outerballoon 514 and retention balloon 516 function in the same manner asouter balloon 456 and retention balloon 454 of FIG. 40 . The balloonscan be of the various configurations described herein, or alternativesthereof. A thermistor can be positioned in lumen 522 or in anotherlumen. In all other respects, the catheter of FIGS. 43-47 functions inthe same manner as catheter 450. Therefore, the discussion of thestructure, features and function of catheter 450 is fully applicable tothe catheter of FIGS. 43-47 .

FIGS. 47A-47C illustrate an alternative embodiment of the catheter ofthe present invention. In these embodiments, the catheter does notinclude the cage. Catheter 530 has an inner drainage lumen 532 having adistal plug or seal 534 which seals the drainage lumen 532 distal of theplug 534 to form a distal region or area 536 sealed from the drainagelumen 532. Positioned within the sealed off region 536 is inner balloon538. Inner balloon 538 has a balloon region 540 receiving fluid contactfrom the outer balloon and a tubular region 542 extending proximallytherefrom. The plug 534 has a recess 534 a (FIG. 48C) to receive tubularregion 542 of the inner balloon 538. Tubular region 542 has an angledregion 543 so that the tubular region 542 is positioned in a separatelumen (lumen 544) than the drainage lumen 532. The distal region 536 canbe of the same diameter as the drainage lumen 532 as shown in FIG. 48Aor alternatively, can be larger (wider) than the drainage lumen 532 asin the embodiment of FIG. 49 showing widened sealed region 536′ ofcatheter 530′. In all other respects, catheter 530′ is identical tocatheter 530 so like reference numerals are used for like parts. Aplurality of openings are provided in distal region 536 for fluidcommunication from the outer balloon through the openings and againstthe outer wall of the inner balloon 538 to deform the inner balloon 538as in the embodiments of FIGS. 35-47 . The catheter can have a cap 531at the distal end to provide a blunt tip for the catheter. The cap 531has a recess 531 a (FIG. 48B) to receive a distal extension of theballoon 538.

Inner balloon 538 functions in the same manner as inner balloon 458.Catheter 530 has an outer balloon 546 and a retention (stabilizing)balloon 548 which function in the same manner as outer balloon 456 andretention balloon 454 of FIG. 40 with inflation lumens 545, 547 (FIG.47B). The balloons can be of the various configurations describedherein, or alternatives thereof. A thermistor can be positioned in lumen544 or in another lumen. Catheter 530 of FIGS. 48A and 48B function inthe same manner as catheter 450 and has e.g., a drainage lumen, a lumenfor inflation of the outer balloon and a lumen for inflation of theretention balloon. Therefore the discussion of the structure, featuresand function of catheter 450 is fully applicable to the catheter 530 andcatheter 530′.

FIGS. 50A-63B illustrate an alternative embodiment of the catheter ofthe present invention that does not include the cage. By placement ofthe inner balloon within the lumen of the catheter without a cage, itreduces the stiffness of the catheter and reduces cost. This embodimentalso has the advantages of keeping the inner pressure balloon centeredto reduce or prevent false pressure readings. The inner balloon expandswithin the inner lumen of the catheter and in preferred embodimentsremains within the confines of the wall of the lumen as the fluid fromthe outer balloon flows through the side openings in the side wall ofthe lumen into pressure contact with the outer wall of the innerballoon.

This embodiment of FIGS. 50A-63B also includes an intermediate balloonforming an inner liner within the outer balloon, discussed in detailbelow, although in an alternate embodiment of the catheter of FIGS.50A-63B, an intermediate balloon is not provided.

Catheter 600 has a retention balloon 604 identical to retention(stabilizing) balloon 206 of catheter 200 (or other stabilizing balloonsdisclosed herein), an inner balloon 608 and an outer balloon 606. Anintermediate balloon 614 is positioned within the outer balloon 606 andexternal of the inner balloon 608.

Turning to FIGS. 56-58D, catheter 600 has four lumens: 1) lumen 644 inwhich inner balloon 608 is positioned (the inner balloon 608 forming thegas, e.g., air filled chamber); 2) lumen 642 communicating withintermediate balloon 614 via opening 642 a for inflating theintermediate balloon 614 and thus expanding outer balloon 606; 3) lumen640 communicating with the stabilizing balloon 604 to inflatestabilizing balloon 604; and 4) drainage lumen 646 having one or moreside openings 610 at a distal end for drainage of the bladder. The sideopening(s) is positioned between the outer balloon 606 and retentionballoon 604, i.e., between the expanded portions of the balloons 606,604. The lumen 644 is also sized to receive thermistor wires fortemperature sensing.

Catheter 600 also has a hub portion with three angled extensions/ports(FIGS. 50A and 50C) at its proximal end: 1) port 620 for access viaopening 623 to inflate the inner balloon 608; 2) port 622 for access viaopening 625 to lumen 642 to inflate intermediate balloon 614; and 3)port 626 for access to lumen 640 via opening 629 to inflate stabilizingballoon 604 via opening 629. Drainage lumen 646 extends linearlyterminating at proximal region 624 in opening 627. Thermistor wires(discussed below) can exit from the catheter port 620 for connection toa temperature monitor via hub 330 (discussed below). Note the locationof the catheter angled ports can vary from that illustrated in FIG. 50A.Also, the location of the lumens and the cross-sectional dimension/sizeof the lumens can vary from that shown in FIGS. 58B-58D as these providejust one example of the location and size, e.g., diameter, of the lumensas well as one example of the shape/cross-sectional configuration andlocation.

In the alternate embodiment of FIG. 50B, catheter 600′ is different fromcatheter 600 of FIG. 50A in that four angled ports are provided. Ports626′, 624′ and 622′ of catheter 600′ are identical to ports 626, 624 and622 of catheter 600 of FIG. 50A and therefore similar components arelabeled with “prime” reference numerals. In this embodiment, anadditional port 621 is provided for the thermistor wires as they do notextend through port 620′ as they do in port 620 of FIG. 50A. Otherwisecatheter 600′ is identical to catheter 600, e.g., it has the retention,outer, intermediate and inner balloons. Note the thermistor wiresextending through port 621 can extend through a separate lumen withincatheter shaft 602′, or alternatively, can extend through the same lumenas the lumen for the inner balloon, but separate at a proximal end toextend through port 621.

A thermistor can be placed adjacent the drainage opening 610 of catheter600 for temperature readings, and the thermistor wire(s) can extendthrough a lumen of the catheter 600 such as lumen 644 for the innerballoon as in catheter 600 or alternatively through the drainage lumenor through a separate lumen, for electrical connection to a temperaturemonitor.

Catheter 600 has an inner drainage lumen 646 having a plug or seal 662(FIG. 54 ) positioned therein which seals the drainage lumen 646 distalof the plug 662. A distal plug 630 is distal of the drainage sideopening(s) 610 so as to not interfere with drainage of the bladder. Thedistal plug 630 also forms a cap at the distal end of the catheter 600to provide a blunt tip.

Distal of plug 662 is a distal region or area 623 which forms anenlarged area of the lumen 644 which receives the inner balloon 608.Inner balloon 608 has a balloon region 608 a and a tubular region 609extending proximally therefrom. Tubular region 609 extends within lumen644 which is separate (independent) from the drainage lumen 646.Thermistor wires discussed below can also extend through lumen 644. FIG.54 shows the enlarged region 623 of lumen 644 which forms a chamber forthe balloon 608. Preferably, there is a gap (space) between the outerwall of balloon 608 and the wall of the lumen forming the chamber. Oneor more openings 644 a (FIGS. 56 and 58B) are provided within thecatheter 600 at the distal region 623 for fluid communication from theintermediate balloon 614 through the opening(s) 644 a and against theouter wall of the inner balloon 608 to deform the inner balloon 608.Thus, the openings 644 a communicate with the chamber 623. The openings644 a can be oval shaped as in FIG. 56 , or alternatively others shapesand sizes. In the illustrated embodiment, two openings are provided,however, additional openings can be provided. These openings provide apassageway for fluid, e.g., gas such as air or saline, from inside theinflated intermediate balloon 614 into contact with the outer wall ofthe inner balloon 608 to deform the inner balloon 608 to provide finerpressure measurements.

The inner balloon 608 has an elongated shape (FIGS. 54 and 60A) withtubular portion 609 extending proximally from the expanded largerdiameter portion 608 a. As noted herein, the elongated tubular portion609 can extend along the length of the lumen 644 and through the sideport 620, terminating at a proximal end in the catheter connector, andattached thereto, as discussed below. For example, the tubular portion609 in some embodiments can have a length of about 600 mm and theexpandable portion 608 a can have a length of about 10 mm, althoughother dimensions are also contemplated. As discussed above, the tubularportion in alternate embodiments can terminate in the lumen distal ofthe connector. Inner balloon 608 has a distal extension 611 attachedwithin opening 631 a (FIG. 61B) in distal extension 631 of distal plug630 via sealing material 632 (FIG. 54 ), such as silicone. A proximalplug 662 is positioned within the lumen 644, adjacent to but proximal ofthe expandable portion 608 a of inner balloon 608 to attach the tubularportion 609 of balloon 608 within opening 644 via sealing material 634such as silicone. Thus, distal and proximal plugs 630 and 662 securelyretain the inner balloon 608 at different sides so it is maintainedwithin the enlarged region 623 centered within the region. That is, inpreferred embodiments, the inner balloon 608 is kept spaced from thewall of the distal region 623 so as not to interfere with flow throughthe openings 644 a which could cause false pressure readings. Innerballoon 608 can be composed of a thermoplastic material, such as PET,which is impermeable to air and not water soluble, but has relativestiffness. Other materials are also contemplated such as EVA.

In an alternate embodiment, the inner balloon can include an innercomponent 639 placed within the inside diameter. The inner component 639(FIG. 60D) is a bead-mandrel which is utilized to decrease the amount ofair charge in the inner sensing balloon 608. Such inner component canincrease the sensitivity of the sensor capabilities. That is, if thereis less air in the inner balloon 608, the balloon is more responsive tochanges in pressure. Thus, by eliminating dead space, it makes it moresensitive. The component 639 can extend the length of the balloon, i.e.,starting at the proximal end of the tubular portion 609 and extending tothe distal tip of balloon 608, or alternatively can extend only along apartial length of the inner balloon 608, e.g., extending only in aportion of the tubular portion 609 and/or the expanding portion 608. Insome embodiments, the inner component 639 can have for example a lengthof about 19 to about 20 inches and an outer diameter of about 0.02inches, although other lengths and diameters are also contemplated. Theinner component to decrease the amount of air in the system can be usedwith the other catheters disclosed herein.

The intermediate balloon 614 can be “pear shaped” or “liberty bellshaped” as shown in FIGS. 54 and 60C. Proximal extension 614 b isattached to an outer surface of catheter 600 at region 617 and distalextension 614 a is attached to an outer surface of catheter 600 atregion 619. The intermediate balloon 614 is positioned within outerballoon 606. In the embodiment of FIG. 54 , the intermediate balloon 614is shaped to form a gap 615 at a distal region between the outer wall ofthe balloon 614 and inner wall of the outer balloon 606, however, inalternate embodiments, the intermediate balloon 614 could more closelyfollow the full contour of the outer balloon 606 so that no gap or asmaller gap would be provided. The distal end of the outer balloon 606can wrap underneath the end of the intermediate balloon 614 forattachment to the catheter outer surface as shown in FIG. 54 , with adistal sleeve 660 positioned over the two ends of the balloons.Alternatively, the outer balloon distal end can remain atop theintermediate balloon distal end in the same manner it does at theproximal attachment at region 617 shown in FIG. 54 . In alternateembodiments, the intermediate balloon 614 can also wrap in the samemanner as the outer balloon 606 of FIG. 54 . In an alternate embodiment,the outer balloon 606 can have one side larger so it inverts on itselfsuch that it would not stick out of the distal end of the cathetershaft.

The intermediate balloon 614 forms an inner liner of the outer balloon606 to therefore act a like a coating to stiffen the outer balloon 606.The intermediate balloon 614 is composed of a material, e.g., athermoplastic material, that is less compliant than the outer balloon606. For example, the intermediate balloon 614 can be composed of EVAwhich would counteract expansion of the more compliant outer balloon606. The outer balloon 606 is composed of a more compliant material suchas silicone. With a compliant balloon, it would continue to expand(stretch) so the pressure would drop. The inner liner prevents this.Note that outer balloon 606 preferably has a smoother surface to shieldthe thermoplastic intermediate balloon 614 during insertion and use toreduce patient discomfort. The intermediate balloon 614 in someembodiments has a wall thickness less than the wall thickness of theouter balloon 606. Note that other compliant/non-compliant materials arealso contemplated.

In an alternate embodiment, upon inflation of the intermediate balloon614, the outer balloon 606 would peel back. Therefore, the outer balloon606 would act as a sheath.

In use, the intermediate balloon 614 is expanded via injection of fluid,e.g. air saline, etc. through the port 622. Expansion of theintermediate balloon 614 causes expansion of the outer balloon 606.Deformation of the outer balloon 606 based on changes in pressure withinthe patient, e.g., within the bladder in response to abdominal pressure,causes deformation of the intermediate balloon 614. As the intermediateballoon 614 is deformed, fluid within the intermediate balloon 614passes through the opening(s) 644 a within the catheter to apply apressure against the outer wall of the inner balloon 606 to deform theinner balloon 606 to provide pressure readings in the same manner as theother embodiments disclosed herein.

Turning back to the transducer hubs mountable to the catheter, FIG. 26illustrates an alternate embodiment of the pressure transducer hub. Inthis embodiment, hub 250 has a shroud 254 (shown schematically)positioned over elongated member 252. This helps protect/shield theelongated member 252. When the transducer 240 is mounted to the port 260of the catheter, the shroud 254 fits over cover 260 of port 218 and isretained by a snap fit or by other methods of securement.

In the aforedescribed embodiments, mounting of the transducer hub a)automatically connects the temperature sensor to a connector forcommunication with a temperature monitor cable; and b) automaticallyadvances air through the first lumen to expand the inner balloon. In theembodiment of FIG. 27 , the pressure transducer hub 270 has a secondelongated member 274 extending therefrom. When transducer hub 270 ismounted to the catheter, e.g., port 218, elongated member 272 enters theair lumen in the same manner as elongated member 242 of FIG. 24A.Additionally, elongated member 274 automatically enters the lumen 210 atport 222 which communicates with the outer balloon 202. Therefore, inthis embodiment, mounting of the transducer hub 270 a) automaticallyconnects the temperature sensor to a connector for communication withtemperature monitor cable as in the embodiment of FIGS. 18-25B; b)automatically advances air through the first lumen to expand the innerballoon as in the embodiment of FIGS. 18-25B; and c) automaticallyadvances air through lumen 210 communicating with the outer balloon 202to inflate (expand) the outer balloon 202. The catheter of FIG. 27 (andFIG. 26 ) is otherwise identical to catheter 200 of FIG. 18A so forbrevity further discussion is not provided since the description of thefunction and elements of catheter 200 are fully applicable to thecatheter of FIG. 27 (and to the catheter of FIG. 26 ).

FIGS. 28A-28D show an alternate embodiment of the hub/connector. Thepressure transducer is external to catheter 280 and mounted to port 282at the proximal end 281 of catheter 280 via connector (housing) 290.Catheter 280 is identical to catheter 200 of FIG. 18A except for theconnector and transducer hub temperature sensor connection.

More specifically, transducer hub or housing, designated generally byreference numeral 300, contains the pressure transducer and sensor 309and is mounted to the angled side port 282. In the embodiment of FIG.28A, the hub 300 is mounted to the catheter 280 by connection to housing290. Housing 290 is connected to port 282 via a barbed fitting 295providing an interference fit with the port 282. The hub 300 is lockedor secured to connector 290 such as by a snap fit provided by the latcharms discussed below, although other attachments are also contemplatedsuch as a friction fit, threaded attachment, other form of latch, etc.,as well as other types of snap fits to provide an attachment thatmaintains an airtight seal so the air is contained within the air lumenand balloon 202 of the catheter 280. (As noted above catheter 280 isidentical to catheter 200 except for its connector so catheter 280includes (not shown) the inner and outer pressure balloons, stabilizingballoon, temperature sensor, etc. The catheter 280 can also have asingle pressure balloon as in the aforementioned embodiments.

The housing 290 attached to catheter 280 has a proximal opening 294 anda channel (lumen) 296 to receive an elongated (rod-like) member or nose302 extending distally from transducer hub 300. As shown channel 296 hasa first diameter region 296 a to match with the lumen 283 of the port282, a second larger diameter region 296 b proximal of region 296 a toreceive the male rod 302 of the hub 300, and a still larger diameterregion 296 c proximal of region 296 b to receive the valve 299 and valve298 and allow expansion thereof. As shown, valve 298 is dome shaped andis distal of valve 299. Conical cap 293, proximal of valve 299, providesa lead in to the valve 299 for the rod 302. Thermistor pins 292 receivethermistor connectors 308. Note valves 288, 299 are one example ofvalves that can be provided as other valves to provide an airtight sealare also contemplated. A single valve is also contemplated.

Hub 300 is mounted to connector 290 and includes a housing 304 fromwhich a pair of distally extending snap fit connector arms 306 extend.The latch arms 306 are sufficiently flexible to enable attachment andhave an enlarged distal portion 307, illustratively shown as arrowshaped although other enlarged shapes could be provided. The elongatedmember 302 extends between the latch arms 306. When the hub 300 ismounted to the connector 290, the elongated member 302 extends into thechannel 296 to advance air to inflate the inner balloon. The enlargedends 307 of latch arms 306 enter recesses 291 and engage shoulders 291 ato retain the hub 300. Note to release (disconnect) the hub 300, theends 307 are pressed radially inwardly to disengage from shoulder 291 aand the hub 300 is pulled proximally. Note that alternatively adifferent number of latch arms could be provided.

The housing (connector) 290 has a lumen 296 for communication with thelumen 283 in the side port 282 of catheter 280 which communicates withthe air lumen and inner balloon of the catheter 280. As noted above, thelumen 296 is dimensioned to receive the elongated rod 302 of transducerhub 300. The wire for the sensor extends in housing 300. When transducerhub 300 is attached to connector 290, such attachment inserts theelongated rod 302 into lumen 296 to advance air though the air lumen inthe catheter and into the balloon 204. (Note the air lumen extends intoits angled side port 282). In the embodiments discussed above whereinthe balloon has a tubular portion, the proximal end of the tubularportion could terminate adjacent the distal end of the rod (elongatedmember of this or other embodiments) or slightly distally thereof or inthe lumen of the side port 283. The elongated member 302 also has achannel or lumen 305 extending therethrough to allow the pressure waveto travel through to the pressure sensor. Although in preferredembodiments no additional air needs to be injected into balloon 204after attachment of hub 300, it is also contemplated that a port oropening can be provided in hub 300 to receive an injection device forinjection of additional air. Such additional air can communicate withand flow through channel 305 of elongated member 302, into the air lumenand balloon 204 for inflation, or alternatively, a side port or openingin the angled port downstream (distal) of the elongated member 302 couldbe provided. Attachment of hub 300 to housing 290 also automaticallyconnects thermistor connectors 308 to thermistor pins 292 toautomatically connect the temperature sensor to the hub 300 forcommunication via a cable to a temperature monitor.

To charge the system, when the hub 300 is mounted to the side port 282via attachment to connector 290, the elongated member 302 extends intolumen 296 to advance air through the air lumen into inner balloon 204(or the pressure balloon in the embodiments with a single pressureballoon) to expand the balloon 204. That is, connection of thetransducer hub 300 to the catheter 280 (port 282) automatically advancesair through the connector lumen 296, the port lumen 283 and the firstlumen 214 (or tubular portion of the balloon) to expand the balloon 204.(Such connection also automatically connects the temperature sensor tothe hub 300). In some embodiments, 0.2 cc of air can bedisplaced/advanced by the member 102, although other volumes are alsocontemplated. Thus, as can be appreciated, mounting of the hub 300 tothe catheter 280 automatically pressurizes the air lumen/chamber andexpands the balloon. Note the balloon can be partially or fully inflated(expanded), dependent on the amount of air advanced into the balloon.Further note that preferably the lumen is not vented to atmosphere whenthe transducer hub 300 is attached and air is advanced through the airlumen. The port 282 includes a closable seal, e.g., valves 298 and 299,through which the elongated member 302 is inserted but maintains theseal when the elongated member 302 remains in the lumen 296. Note thatcatheter 280 is identical in all other respects to catheter 200 so thatthe description of catheter 200 and its components and function (andalternatives) are fully applicable to catheter 280, the difference beingthe connector 290 of catheter 292 to receive transducer hub 300. Thetransducer hub is also different, e.g., has latch arms and a differentconfiguration.

In the alternative embodiment of FIGS. 29A-29C, the latch arms arereversed so that they are located on the connector rather than on thetransducer hub as in FIG. 28A. More specifically, transducer hub(housing), designated by reference numeral 320, has an elongated member322 with a channel 323 and is identical to elongated member 302 of FIG.28A for advancing air through the lumen and into the pressure balloon.Pressure transducer 324 is contained within the housing 320. Recesses325 are dimensioned to receive the latch arms 317 of the connector orhousing 310 which is connected to the side port 282 of catheter 280.(Catheter 280 is the same as catheter 280 of FIG. 28A except forconnector 310). Extending proximally from housing 310 are two latch arms16 with enlarged region 317 which engage the shoulders 326 formed byrecesses 325 in hub 320 in a similar manner as latch arms 306 of FIG.28A engage in recesses 291 and shoulder 291 a. Connectors 328 in hub 320engage thermistor pins 312 of connector 310 for connection of thetemperature sensor. Connection of the hub 320, like hub 300,automatically advances air to inflate the pressure balloon andautomatically connects the temperature sensor.

To disconnect (release) the hub 320, ends 317 of latch arms 316 arepressed radially inwardly to disengage from shoulder 326 so hub 320 canbe pulled proximally out of connector 310.

In the alternate embodiment of FIGS. 64-69 , the transducer hub orhousing, designated generally by reference numeral 330, contains thesensor (pressure transducer) and is mounted to the angled side port 620of catheter 600. The hub 330 is mounted to the catheter 600 byconnection to housing (connector) 670. Housing 670 is connected to port620 via a barbed fitting 677 (FIG. 66A) providing an interference fitwithin the port 620. The hub 330 is locked or secured to connector 670such as by a snap fit provided by the latch arms 332 discussed below,although other attachments are also contemplated such as a friction fit,threaded attachment, other forms of latch, etc., as well as other typesof snap fits to provide an attachment that maintains an airtight seal sothe air is contained within the air lumen and balloon of the catheter600.

The housing (connector) 670 attached to catheter 600 has a proximalopening 672 and an internal channel (lumen) 680 (FIG. 65 ) to receive anelongated (rod-like) member or nose 334 extending distally fromtransducer hub 330. As shown, channel 680, which communicates with lumen620 a of port 620 has a first diameter region 680 b, a second largerdiameter region 680 a proximal of region 680 b to receive the male rod334 of the hub 330, and a still larger diameter region 680 c (FIG. 69 )proximal of region 680 a to form a receptacle for O-ring 682. Thisconfiguration of channel 680 provides a region larger than the OD of therod 334 so it is not a one-one ratio. In a one-one ratio, a smallpressure drop in the balloon would result in a large pressure drop inthe system. Thus, the channel 680 is configured/sized to provide extravolume to act as a capacitor to slow down the percentage pressure lossand stabilize the pressure readings due to loss of air when compressed.The channel 680 has a distal larger diameter region 680 d extending fromnarrowed region 680 b to form a funnel for entry of the tubular portion609 of the inner pressure balloon 608. The tubular portion 609 of theinner balloon 608 in manufacture is slid into/pressed into the funnel680 d until it cannot go in any further due to the reduced channelportion 680 b. The tubular portion 609 of balloon 608 can be glued intoplace within region 680 d. Note that in the illustrated embodiment, thetubular portion 609 of inner balloon 608 would extend into and throughside port 620 into connector 680 d. However, in alternate embodiments,the tubular portion 609 of balloon 608 could terminate further distallywithin angled port 620, and in some embodiments could terminate evenfurther distally, i.e., within catheter lumen 644 so that air would beadvanced by rod 334 through lumen 644 and then into the tubular portion609 through a proximal opening in tubular portion 609 communicating withlumen 644.

Instead of valves as in the embodiment of FIG. 28D, two O-rings 684, 682are seated within connector 670 with O-ring 682 positioned in support orcup 676 and O-ring 684 positioned distal of support 676 in a recess inconnector 670. Thermistor barrel shape receptacles 678 (FIGS. 66C, 67and 68 ) receive thermistor connectors or pins 335 (FIG. 64 ), and ametal piece (receptacle) is positioned within each plastic barrel 678,each forming a female receptacle for the male pin(s) 335. The thermistorwires 679, shown in FIGS. 66B and 66C, extend from the thermistor,positioned in the catheter 600 adjacent the drainage lumen, throughlumen 644 and through side port 620. (Alternatively, the wires canextend through a separate lumen in the catheter). The two wires 679extend through an elongated groove 673 a and slot 673 c in conicalconnector part 673, and are then wrapped (spooled) around shaft 681 andretained by flange 673 b. The wires 679 extend through the flange 673 band are split to each electrically connect with a metal piece(receptacle) in one of the female connector barrels 678. C-shapedextension 671 a of cover 671 is inserted into slot 673 c covering thewires 679. When cover 671 is placed over holder 673, the wires 679 arehidden to protect the wires. Thus, as can be appreciated in the view ofFIG. 64 , once assembled, the wires 679 are not visible.

Hub 330 is mounted to connector 670 and includes a housing 331 fromwhich a pair of distally extending snap fit connector arms 332 extend.The latch arms 332 are sufficiently flexible to enable attachment andhave an enlarged distal portion 332 a, illustratively shown as arrowshaped although other enlarged shapes could be provided. The elongatedmember (rod or nose) 334 extends between the latch arms 332. When thehub 330 is mounted to the connector 670, the elongated member 334extends into the channel 680 of connector 670 to advance air thoughinner balloon tubular portion 609 to inflate the inner balloon 608. Theenlarged ends 332 a of latch arms 332 enter recesses 674 and engageshoulders 674 a to retain the hub 330. The arrowhead tips of the latcharms 332 are at an acute angle to create a positive lock so that onceengaged with the shoulder 674 a, the hub 330 cannot be pulled proximallyunless the latch arms 332 are released. To release (disconnect) the hub330, the ends 332 a are pressed radially inwardly to disengage fromshoulder 674 a and the hub 330 is pulled proximally. Note thatalternatively a different number of latch arms could be provided. Thedistally extending thermistor pins 335 engage thermistor connectorswithin barrels 678 of connector 670 which have an interior stop to limitinsertion of hub 330. This connection of the hub 330 and connector 670limit lateral and longitudinal movement to ensure accurate pressurereadings as lateral movement, for example, could change the pressure.The longitudinal movement is restricted in a proximal direction by thelatch arms/shoulder engagement and in a distal direction by the fullinsertion of the thermistor pins 335 or alternatively by engagement ofthe hub 330 and housing 670 distal and proximal surfaces. The O-ringengagement of the elongated rod 334 limits lateral movement of the rod334 and therefore restricts lateral movement of the hub 330.

Printed circuit board 336 containing the pressure sensor is mountedwithin hub 330. It can be bonded to a support within the hub. Note adigital pressure sensor can be used instead of an analog sensor in thisembodiment as well as the other embodiments disclosed herein.

When transducer hub 330 is attached to connector 670, such attachmentinserts the elongated rod 334 into lumen 680 to advance air though thetubular portion 609 of the inner balloon 608 and into the inner balloon608 to inflate the balloon 608. The elongated member 334 also has achannel or lumen 337 (FIG. 65 ) extending therethrough to allow thepressure wave to travel through to the pressure sensor of PCB 336.Although in preferred embodiments no additional air needs to be injectedinto balloon 608 after attachment of hub 330, it is also contemplatedthat a port or opening can be provided in hub 330 to receive aninjection device for injection of additional air. Such additional aircan communicate with and flow through channel 337 of elongated member334, into the tubular portion 609 and inner balloon 608 for inflation,or alternatively, a side port or opening in the angled port downstream(distal) of the elongated member 334 could be provided. Attachment ofhub 330 to housing 670 also automatically connects thermistor connectors(within barrels 678) to thermistor pins 335 to automatically connect thetemperature sensor (within the catheter) to the hub 330 forcommunication via a cable to a temperature monitor.

In use, to charge the system, when the hub 330 is mounted to thecatheter side port 620 via attachment to connector (housing) 670, theelongated member 334 extends into lumen 680 to advance air through thelumen into balloon 608 to expand the balloon 608. That is, connection ofthe transducer hub 330 to the catheter 600 (port 620) automaticallyadvances air through the connector lumen 680 and tubular portion 609 toexpand the inner balloon 608. Such connection also automaticallyconnects the temperature sensor to the hub 330. In some embodiments, 0.2cc of air can be displaced/advanced by the elongated member 334,although other volumes are also contemplated. Thus, as can beappreciated, mounting of the hub 330 to the catheter 600 automaticallypressurizes the air lumen/chamber and expands the balloon. Note theballoon can be partially or fully inflated (expanded), dependent on theamount of air advanced into the balloon. Further note that preferablythe lumen is not vented to atmosphere when the transducer hub 330 isattached and air is advanced through the air lumen.

Note the lumen which is used to inflate the pressure balloon and createthe air column has an opening at a distal region to communicate with theinterior of the pressure balloon. If an outer balloon is provided, anadditional lumen can be provided in the catheter to communicate with theouter balloon to fill the outer balloon and an additional angled port(extension) at the proximal end of the catheter would receive aninflation device to inflate, either fully or partially, the outerballoon.

Note in each of the embodiments disclosed herein, air is described asthe preferred gas for creating the column and expanding the balloon,however, other gasses are also contemplated for each of the embodiments.

The pressure balloons of the embodiments herein can be symmetricallyshaped as shown or shaped such that a distal region has an outertransverse cross-sectional dimension, e.g., diameter, greater than anouter transverse cross-sectional dimension, e.g., diameter, of theproximal region. A smooth transition (taper) can be provided between thedistal region and proximal region, although other configurations arealso contemplated. The inner (and outer) balloon can by way of examplebe made of urethane, although other materials are also contemplated.

The wire connector of the foregoing embodiments can plug into theopenings of a connector positioned on or in the hub. The wire connectorcan be internal of the hub with an opening in the wall of the hub toenable access for the wire connector. Also note that alternatively thewire can include a female connector and the hub can have a maleconnector. Other types of connectors/connections are also contemplated.

In alternate embodiments, any of the catheters disclosed here caninclude a pulse oximetry sensor to measure oxygen saturation in theurethral or bladder tissue. The sensor can be located either proximal ordistal to the pressure balloon and/or either proximal or distal to thestabilizing balloon. It could also alternatively be mounted within oneof the balloons.

It is also contemplated that in some embodiments a backup system beprovided to determine pressure. The backup system can provide a doublecheck of pressure readings to enhance accuracy. Such backup system canbe used with any of the embodiments disclosed herein to provide a secondpressure reading system. One example of such backup system is disclosedin FIGS. 14A and 14B. In this embodiment, catheter 160 has the pressuretransducer/pressure sensor 162 like sensor 30 of FIG. 1 within the air(or other gas) lumen 164 communicating with pressure balloon 167,forming a “first system”, plus a pressure transducer/pressure sensor 169at a proximal end of the catheter as in FIG. 12 or external of thecatheter forming a “second system”. Thus, the pressure sensor 162 is ata distal end of the air charged lumen 164 and pressure sensor 169 is atproximal end of the air charged lumen 164. Both sensors 162 and 169 areelectrically connected to a monitor which provides a graphic display ofpressure readings. The catheter 160 also includes a temperature sensoreither as part of the sensor 162 or a separate component that can bepositioned for example in the lumen 164 distal of sensor 162 as in theembodiment of FIG. 8 . A stabilizing balloon 168 and an inflation lumento inflate balloon 168 can also be provided. Lumen 163, having a sideopening 170 at its distal end, which can be located distal or proximalof balloon 167, is configured to drain the bladder similar to lumen 20and side opening 22 of the embodiment of FIG. 1 .

In use, catheter 160 is inserted into the bladder and stabilizingballoon 168 is inflated to secure the catheter 160 in place. The systemis charged by inflation of the balloon 167, i.e., preferably partiallyinflated for the reasons discussed above, by insertion of air throughside port 172 which is in fluid communication with the air lumen in aclosed system formed by the internal space of the balloon 167 and theinternal lumen 164 communicating with the internal space of balloon 167.With the balloon 167 inflated, pressure monitoring can commence asexternal pressure applied to an outer surface of the balloon 167compresses the air (or other gas) within the chamber. The sensor 162 atthe distal end of lumen 64 provides continuous pressure readings,converted to an electrical signal by the transducer within the distalend of lumen, and then electrically communicates through itstransmission wires extending through the air lumen to an externalmonitor either directly or via a converter. Additionally, pressurewithin the air charged column is measured at a proximal region by sensor169 within side port 172 of catheter 160. The sensor 162 at the distalend of lumen 164 provides continuous pressure readings, and suchpressure readings can be confirmed by the proximal sensor. Such pressurereadings can be performed continuously (along with continuoustemperature monitoring) or alternatively can also be adapted if desiredfor periodic monitoring so the pressure and/or temperature readings canbe taken at intervals or on demand by the clinician. Thus, air pressurereadings at a proximal end plus microtip pressure readings at the distalend are provided. The sensors 162 and 169 can electrically communicatewith an external monitor to display both pressure readings from sensors162, 169, or alternatively, if the pressure readings are different, theycan be averaged to display a single measurement. Clearly, other displaysof information can be provided to display the information from the twosensors 162, 169.

The sensors disclosed herein can be microtip sensors within the air (orother gas) lumen or balloon. In alternative embodiments, fiber opticsensors within the air (or other gas) lumen or balloon can by utilizedto transmit circumferential/area pressure. The pressure transducers canbe housed within the catheter or alternatively external to the catheter.Additionally, core temperature sensors can be part of the pressuresensor or a separate axially spaced component.

The multi-lumen or single lumen catheters disclosed herein provide anair (or other gas) charged balloon (air containing chamber) givingprecise readings of intra-abdominal pressure (or for other pressuremeasurements) and the systems are charged via insertion of air through aside port. The multi-lumen catheters are easily inserted into thebladder in the same manner as standard bladder drainage catheters andenable continuous drainage of urine while continuously recording IAPwithout interrupting urine flow and without requiring retrograde fillingof the bladder with water. Thus, these catheters provide a closedsystem. The catheters also have a balloon providing a large reservoir(large capacity) and large circumferential area/interface for obtainingmore information from the bladder over multiple reference points (ratherthan a single point sensor) that provides an average pressure to providea more accurate assessment of the surrounding environment as pressuremeasurement is not limited to one side of the bladder but can determinemeasurements on the opposing side as well. The balloon can have asufficiently large circumferential area so that it is in contact withthe bladder wall, and in some embodiments, could distend the bladderwall, thus enabling pressure measurement without insertion of fluid intothe bladder. When used in other body cavities for other pressuremeasurements, the pressure balloon of the multi-lumen or single lumencatheters disclosed herein can be of sufficiently large to contact or insome embodiments, distend the cavity wall, thus enabling pressuremeasurement without insertion of fluid into the cavity. The balloon, asnoted above, of the multi-lumen or single lumen catheters disclosedherein can be impermeable or have an impermeable membrane (as definedherein) to prevent escape of gas to prevent loss of accurate pressurereadings.

As noted above the catheters in some embodiments can be connected to abedside monitor through either a wire or blue-tooth wireless connection.The system can also in some embodiments include an indicator or alarmsystem to alert the staff at the site as well as remote staff throughwired or wireless connections to external apparatus, e.g., hand heldphones or remote monitors.

As noted above, an alarm or indicator can be provided in someembodiments to alert the staff. The indicator can be a visual indicatorsuch as a light, LED, color change, etc. Alternatively, or additionally,the indicator can be an audible indicator which emits some type of soundor alarm to alert the staff. The indicator can be at the proximal regionof the catheter or at other portions of the catheter, e.g., at a distalend portion, where known imaging techniques would enable the user todiscern when the indicator is turned on. It is also contemplated that inaddition to providing an alert to the user in some embodiments, thepressure monitoring system can be tied into a system to directly reduceabdominal pressure so that if the pressure exceeds a threshold level(value), the abdominal pressure can automatically be reduced. In suchsystems, an indicator can be provided on the proximal portion of thecatheter, e.g., at a proximal end outside the patient's body, orseparate from the catheter. The sensor can be in communication with theindicator, either via connecting wires extending through a lumen of thecatheter or a wireless connection. The sensor can be part of a systemthat includes a comparator so that a comparison of the measured pressureto a predetermined threshold pressure value is performed and a signal issent to the indicator to activate (actuate) the indicator if themeasured pressure exceeds the threshold pressure to alert the clinicianor staff that pressure within the abdomen is too high and a signal isalso sent to a device or system to automatically actuate the device orsystem to reduce the abdominal pressure. If the measured temperature isbelow the threshold, the indicator is not activated. A similar systemcan be used for temperature measurement and indication.

It is also contemplated that a micro-air charged sensor could beprovided in the retention (stabilizing) balloon.

It is also contemplated that microtip sensors and/or fiber optic sensorscan be utilized to measure pressure, and these sensors can be utilizedinstead of or in addition to the air pressure readings utilizing theaforedescribed balloon(s) for measuring pressure.

Pulse oximeters for measuring oxygen levels (oxygen saturation) in theurethral and/or bladder tissue could also be provided. In someembodiments, the pulse oximetry sensors can be positioned on thecatheter proximal to the retention balloon. Alternatively, the sensorscan be positioned within the retention balloon, on the catheter distalto the pressure balloon or on other regions of the catheter. Anotherchannel in the catheter can be provided for the sensor and its connectorto external devices, e.g. readers.

The catheters disclosed herein are designed for insertion into thebladder. However, it is also contemplated that they can be adapted forinsertion into the rectum, colostomy pouch, stomach, supra-pubic bladderdrain, or other orifice directly connected with the abdominal cavity.They can also be inserted into other areas connected with othercavities. Uses include by way of example, cardiac use, labor anddelivery use, rectal placement for abdominal cavity, use for gastricpressure, esophageal motility, endocranial pressures ERCP, gall bladder,etc.

Although the apparatus and methods of the subject invention have beendescribed with respect to preferred embodiments, those skilled in theart will readily appreciate that changes and modifications may be madethereto without departing from the spirit and scope of the presentinvention as defined by the appended claims.

What is claimed is:
 1. A catheter insertable into a patient formonitoring a pressure within the patient, the catheter comprising: afirst lumen; an expandable outer balloon at a distal portion of thecatheter, the outer balloon having a first outer wall configured toreceive a fluid to move from a first condition to a more expandedcondition, the outer balloon configured to expand radially outwardlywith respect to the catheter; an expandable inner balloon, the innerballoon having a second outer wall and an elongated portion extendingproximally into the first lumen, the elongated portion having a reduceddiameter, the inner balloon configured to receive a gas within a gascontaining chamber to monitor the pressure within the patient, the innerballoon configured to move from a first condition to a more expandedcondition; wherein the outer balloon has a circumferential area greaterthan a circumferential area of the inner balloon; wherein the outerballoon and the inner balloon are configured such that when the outerballoon and the inner balloon are each in the more expanded condition,in response to a first pressure exerted on the first outer wall of theouter balloon, the fluid within the outer balloon exerts pressure on thesecond outer wall of the inner balloon to deform the inner balloon andcompress the gas within the inner balloon; wherein the outer balloon isconfigured to deform the inner balloon to compress the gas within theinner balloon to provide a pressure measurement.
 2. The catheter ofclaim 1, wherein the outer balloon is configured to be inflated via asecond lumen independent of the first lumen.
 3. The catheter of claim 1,further comprising a chamber, the chamber containing a plurality ofopenings communicating with an interior of the outer balloon.
 4. Thecatheter of claim 1, wherein the inner balloon in the more expandedposition is configured to remain within confines of the first lumen. 5.The catheter of claim 1, wherein the catheter comprises an additionallumen and a stabilizing balloon, the additional lumen communicating withthe stabilizing balloon to inflate the stabilizing balloon to stabilizea position of the catheter, the stabilizing balloon positioned proximalof the outer balloon.
 6. The catheter of claim 5, wherein the catheterfurther comprises a third lumen communicating with a bladder of thepatient, the third lumen configured to remove fluid from the bladder,and the third lumen has a side opening proximal of the inner balloon andthe outer balloon, the side opening positioned between the stabilizingballoon and the outer balloon.
 7. The catheter of claim 1, wherein eachof the inner balloon and the outer balloon has a coating to increaseimpermeability.
 8. The catheter of claim 1, wherein the catheter has atemperature sensor positioned within the catheter to measure core bodytemperature.
 9. The catheter of claim 1, further comprising a hubconfigured to connect to a first port of the catheter, wherein the hubis configured such that the connection of the hub to the first portautomatically advances air into the inner balloon to expand the innerballoon via an elongated member.
 10. The catheter of claim 1, whereinthe elongated portion of the inner balloon is a tubular portion, andfurther comprising an elongated member positioned within the tubularportion of the inner balloon.
 11. The catheter of claim 1, wherein thefirst lumen has a wall with at least one side opening, and the fluidwithin the outer balloon enters the at least one side opening to exertpressure on the second outer wall.
 12. The catheter of claim 1, whereinthe gas containing chamber is an air containing chamber.
 13. Thecatheter of claim 1, further comprising thermistor wires extending inthe first lumen.
 14. A catheter insertable into a patient for monitoringa pressure within a body cavity without insertion of fluid into the bodycavity, the catheter comprising: a wall having at least one sideopening; an expandable outer balloon at a distal portion of thecatheter, the outer balloon having a first outer wall and wherein theouter balloon is configured to move from a first condition to a moreexpanded condition when balloon expanding fluid is received within theouter balloon; an inner balloon configured to move from a firstcondition to a more expanded condition, the inner balloon having asecond outer wall and the inner balloon configured to receive a gaswithin a gas containing chamber, the second outer wall of the innerballoon radially spaced from the first outer wall of the outer balloon,the inner balloon having a reduced diameter elongated portion extendingproximally into a lumen of the catheter, the outer balloon beingconfigured to act as a medium for transfer of the balloon expandingfluid within the outer balloon to the second outer wall of the innerballoon to deform the inner balloon, the inner balloon configured tomonitor fluid pressure; wherein the outer balloon and the inner balloonare configured such that when each are in the more expanded condition,in response to a first pressure exerted on the first outer wall of theouter balloon which deforms the outer balloon, the balloon expandingfluid within the outer balloon exerts pressure on the second outer wallof the inner balloon to deform the inner balloon and compress the gaswithin the inner balloon to provide a pressure measurement; wherein theouter balloon is configured to provide the balloon expanding fluid toenable multiple additional pressure measurements multiple times during aprocedure without the insertion of fluid into the body cavity.
 15. Thecatheter of claim 14, further comprising a drainage lumen communicatingwith the body cavity to remove body fluid from the body cavity.
 16. Thecatheter of claim 14, wherein the elongated portion of the inner balloonforms an elongated channel, and the gas containing chamber includes theelongated channel and the inner balloon.
 17. The catheter of claim 14,wherein the second outer wall of the inner balloon is configured to notexpand outside the lumen of the catheter when the inner balloon is inthe expanded condition.
 18. The catheter of claim 14, further comprisingan inner component extending into the elongated portion of the innerballoon.
 19. The catheter of claim 14, further comprising thermostatwires extending into the lumen.